There is a rare person who can honestly say that their RL feelings don't transfer into their 3D selves. After all, you're a real person behind that avatar, right? Exactly.
It's nearly impossible to participate in a 3D world and not have your very real feelings affected, and this is especially true when it comes to love relationships.
The only people that can truly treat it as a "game" are those who have relationship/caring problems in real life. There's quite a few of them out there; in many cases, they get involved and suddenly find that they are indeed having true feelings for this other person, just as if they'd met and dated them in real life.
I can clearly recall someone I used to know on SL talking to me about how hurt they were over their pixellated relationship, and not understanding why. It was a new experience for him; he clearly never thought his "real self" extended into the world, and could feel "real" feelings about what was happening to him.
That is why it is of the utmost importance that you participate in online relationships with unbridled honesty. It's so hard to communicate in text as it is; if you don't let your 3D partner know what's going on with the REAL you, things will fall apart very quickly.
In my case, the other person said right out front they didn't want anything to go beyond the 3D world, and yet, as time went by and we spent more time talking out-of-character, we ended up developing a very deep, precious friendship, technically "breaking" the rule she had in her profile about not seeking anything beyond online.
We also wrap a lot of our personal selves into the avatar that we play. In my opinion, it's inevitable because it's an extension of our true selves - and often has the same strengths, failings, and foibles of the real us. In my experience with the Internet, I've noticed that the environment in general tends to amplify all that is good and bad about us. My theory is this happens because we are interacting via our "ethereal" selves, the selves that inhabit our living body. We can use our living body to hide or obfuscate a lot of things; also, face-to-face spawns a lot of unconscious cues, both for honesty, and for obfuscation.
We don't have our living bodies to "hide in" on the Internet. Our cerebral selves are out there, bereft of the cloak of flesh, for good or for bad.
If you are a person who tends to be secretive, or dishonest, or otherwise portray yourself to the world as other than you really are, it'll become ten times as obvious on the Internet, where your cloak of flesh is stripped away.
If you are naturally an honest, open person, this likewise will become ten times as obvious.
3D virtual worlds opened up a whole new vista of cerebral interaction, because we wrapped ourselves in pixellated flesh, and yet we are still interacting with others on a very cerebral level. The pixellated flesh you see is going to stimulate your sexual desires and it is going to trigger behaviors that we would display, if we saw the same thing in real life - only here, you can't hide how you feel behind a mask so easily.
There are different "rules" governing this 3D interaction that a great many people weren't prepared to deal with, being stripped bare of their usual defenses. There is far less tolerance for bigotry, racism, and the like. Conversely, there is a far greater chance you will "fall" for someone else, first by the visual stimulation of the avatar, then by the cerebral stimulation of your feelings.
Others have talked about it, so all I am going to do is reiterate it- there is nothing "fake" about you in virtual reality, and there is nothing "fake" about others, either. We all are who we are, whether we came in with the idea of meeting new, "real" people, or to roleplay a character. There doesn't exist a switch where you can turn off your feelings or detach them from a situation that you are participating in, using your mind. After all, it's your mind that's running your flesh, isn't it? Why did you think that somehow got "detached" when you ventured forth mentally into a 3D avatar?
3D interaction is just as real, just as valid, as concrete world interaction. It's just another venue. Human beings are a constantly evolving species, and that includes constantly evolving methods of communication. We are spirits inhabiting flesh bodies who (one hopes) are on a personal evolution.
Our own culture has tried to teach us that subterfuge and dishonesty are things that gain you what you want - at least that's how it seems when you see one dishonest person after another gaining what you feel is your reward for behaving in an honest, decent manner. It can be very confusing, and can also lead to us being blind to our own level of honesty. We may believe we're the most honest person in the world, and then a situation will come along which requires bald-faced honesty and we fall flat on our faces, or feel very exposed and vulnerable. A sense of vulnerability can be handled two ways: It can be embraced without letting others take gross advantage of us, or it can be seen as a weakness, and obfuscated by less than what most people consider honesty.
Vulnerability is hardly a weakness. It's what keeps us able to love and be loved. It shows us where we need to improve things in ourselves. It's not something to be hidden, derided, or otherwise put down. It's a very important part of the human condition.
So what makes some people think they're "less than human" if they're interacting via a pixellated avatar? Can you "touch" your feelings or thoughts? They're just as incorporeal as that avatar, but no less real.
Internet interaction, 3D and otherwise, is free of the constraints we face in the concrete universe, which can make it far more tricky, to put it mildly. For some people, the freedom means they treat others any old way they want, without regard to the damage they may cause. We tend to carry our personal ethics with us, no matter where we go, physically or otherwise. We also carry our experiences, lessons learned, lessons avoided, and personal baggage. When we venture into a universe without the usual cultural and legal controls, it is a real test of our personal foundations. Do we have a solid core of ethics which cause us to apply a "golden rule" to others by nature, or are we conflicted and therefore treat others in a conflicted manner? It provides a basis for true introspection, and sometimes what we find isn't very pleasant. That holds true for everyone, even if they DO have a solid core of ethics.
I am a person who takes others at their word. I also make it clear that I will give honesty and expect it in return. Not the "nice" kind of social honesty most are familiar with, but the kind of honesty that leaves you knowing precisely where you stand with me, good and bad. Part of what I "carry" into the Internet includes all the psychological therapy I've had in my life, and the growth which has come from it. Another part is my experience as an adult child of alcoholics, and my growth as a result of Al-Anon, Alateen, and outpatient group therapy. I've been through a lot, and I've come out a far more grounded person as a result. Before you think this means I think I'm perfect, I'm not. I'm just as prone to mistakes as the next person. However, I approach life with the general attitude of gentleness, and I go hoping that others will do the same for me. We're all human.
When someone says they have a boundary, I respect it. When they give me clear and unambiguous clues that they want to venture beyond that boundary, I will check with them, then proceed. This is precisely what happened with my last online relationship, and exactly what led to its demise, because the honesty I needed when the tides shifted wasn't provided to me.
If you are a veteran roleplayer as I am, it's critically important that you're on the same page as your roleplay partner(s) or personal feelings can, and will, be hurt. You invest yourself into your character, whether you play that character on paper, on a board, on a forum, or in a 3D world. You have the added element of far more of yourself being invested if you take this character from simple paper to a fledged being, especially if you give it 3-dimensional life. Therefore it is critical to all happiness involved that you know exactly what is going on.
I am a far more happier person, overall, if I know exactly what is going on, so the sudden turn of events in my online relationship had a definite impact on me, especially since the real person playing the other character did not tell the real me just what was going on. Lots of accusations flew back and forth, and hearts were broken in the end.
I may be an Empath in real life. I am even a touch telepathic...but I am intelligent enough, and I have enough respect for other people, that I do not rely on these personal Talents alone to give me information about another. I will ask directly what is going on. When I did in this case, it got messy and very hurtful, and in the end, led to the destruction of a very deep, very real personal bond.
There is nothing "fake" about virtual reality. We are who we are no matter where we present ourselves, so it is very important that we do the best we can. I see my involvement in 3D worlds as just another variation on reality. No, I don't think I'm a fae cat in real life, but my personality IS real, and drives that fae cat. I am the same person, no matter how you meet me - by phone, by Internet, or in real life. I make my intentions very clear with people, and I make my base expectations very clear as well. If you agree to meet those expectations and fail to, that is on you, and not on me. That is true for anyone, no matter who or what they are.
It's far too easy for people to dismiss an online "marriage" or partnering as not real, but in doing so, they deny their very humanity. The interaction triggers the exact same responses in your thoughts and feelings as a real-life marriage or partnering would. You have certain expectations, and, if you're like me, you make those clear, so there is no doubt. If the other person doesn't take things as seriously, and/or views them as "play", then you're in for a world of hurt.
Don't forget your humanity when venturing into other realms of interaction.
UPDATE: I decided to add this link to a post I made in my personal (non VR worlds) blog, because polyamory often walks hand-in-hand with virtual relationships. This is true whether you have a spouse offline and another online, or several love interests online. I hope you enjoy this as well.
On Polyamorous Relationships