I'm sorry, but again, there is romance and then there is sex. Romance can lead to sex, but sex does not mean romance is taking place. Likewise, intimacy does not necessarily mean sex either. Two people can share very tender, open and meaningful moments together without having sex. Sex, when done right, is the ultimate and deepest level of romance and intimacy; becoming as one physically.
This said, most intimacy moments can be played out in a video game without an actual sex scene. It doesn't have to show two people making out, one climbing on the other, clothes being removed, or whatever. As some have stated, this is really hard to do well in a video game anyway. So, you don't need a steamy sex scene in a video game to show vulnerability, etc.
Again, I thought BG2 did rather well with Jaheira's romance. She expressed her vulnerability through dialogue with the MC. You couldn't even see animations of her face or inflections or anything, but you could feel it in the voice actress' voice. It was in the dialogue itself that you began to feel Jaheira's pain and such. Sure, her romance led up to a moment when you could agree to have sex with her, but there was no need for any kind of graphic representation of it.
I just want to point out that the most ADULT thing you can do in this video game is maybe NOT date your co-workers.
I reject everybody, not because I am prude, but because I am the boss and I don't want us to wind up in the D&D equivalent of HR. :P