Not gonna lie, I would be less hurt if he left me for a guy than a girl. If he was with me it's completely different than being with a guy, he's going to have completely new experiences with him and won't compare much to me or me to him. If he got with a girl I would always compare myself to her, if I were prettier or had bigger boobs or a bigger ass or if I was her body shape and how she's probably tighter than me or tastes better or she can probably deepthroat or agrees to anal or something.. I would definitely rather he get with a guy than a new girl
I would care about the rejection of course but I would actually feel better in that it had nothing to do with me being a pretty enough girl. In your case, you wouldn't have to feel insecure in relation to other guys, she doesn't like any of them. And since you're not going to become a woman, it just is what it is.
I'd understand- because I mean, have you met women? They're so much better than men in like... every way? I mean sure they bleed, but compared to men? I mean really? We're hairy, smelly, we have penises (have seen a penis? they look like dead chickens or some shit), we take massive stinking shits and we don't even have breasts to make up for it.
If my girlfriend left me, I would be hurt. If she left me for a lesbian, would it hurt more? No. If my girlfriend likes girls, then please don't waste my time or marry me. What was the sex like? Was she into it/you?
I would not. She is just now comfortable with the fact that she is a lesbian, and wants to be honest about it. It doesn't mean that she doesn't have love and respect for you, just that her sexual attractiveness is towards another.