He sister sounds mean, but your girlfriend sounds like she was just trying to get her sister to let it go. Your girlfriend stuck up for you and I bet she wouldn’t be with you if she were not attracted to you. She even said being intimate with you was great. She obviously adores you and I would focus on that.

Also, there’s a lot more to a person’s attractiveness than just how they look in a picture (obviously, no idea if this even applies to you). Some of the most attractive, wonderful people I’ve met in my life are not what society would call “good looking” but when you talk to them, their mannerisms, how they make you laugh, their intelligence, the way they speak…..suddenly they become the most attractive person in the room. And I think that’s what you are to your girlfriend.