again,
personally, i do feel that all's fair in love and war and that morality doesn't really come into play... eros love is anything but altruistic....
but my personal call for karma is related to my interpretation of the biblical call not to judge... it may be because it takes a personal, psychological toll on YOU.
having perpetrated, you may ever more see yourself as a victim of it... like how murderers fear murder like no other (this i get purely from the movies... but it feels true)....
it may wear down the psychological resources you have for yourself if it should ever happen to you.
anyhoo, as i said at first, whatever you do, you gotta live with it. and if you can, you're set.
delta
p.s. but an interesting point has been made. why go for a chick that's already taken (however rudimentarily)? by your account, you're quite the catch and can have anybody. and the world is FULL... CHOCK FULL of hot chicks that are single. no matter how hot she is, she isn't SINGULARLY SPECTACULARLY HOT is she? all hot chicks are a dime a dozen. so why go after one that's attached?
it sounds like you're trying to rescue her maybe but that can be a kind of a pathological complex too....