This happened about a year ago and I still feel like my relationship with her was damaged and I want to move on.
She was 16 at the time and had my snapchat username because my brother once used my phone to snapchat her when his battery died. She began snapchatting me (along with her friends, I assume) pictures of my brother where she called him 'gay', used the pronoun 'it' to describe him and drew penises all over his face. I found it incredibly immature and, as a bisexual woman who was closeted at the time, I was really hurt and put in a very uncomfortable position. She knew I was big on the whole equality thing and have a grandmother in a same-sex partnership at least, so I was floored that she thought that was a good early impression to make. Even if I was straight, I'd have been disgusted. Anyway, I eventually confronted her (having to out myself to my family in the process, yippee, thanks girl) and it just didn't go well. Things were kind of patched up but I'm still not happy to spend time with this girl. I don't hate her, I just don't have a good impression of her.
However, the two of them are getting pretty serious (well, they're 17 and 18 now, so as serious as they can be at that age) and it's starting to look like there's a non-negligible chance this girl will be around for a while, if not married to my brother someday. I'm sure many of you have had unpleasant conversations with in-laws/SOs of family members, how do you move past it? Are you ever able to pretend it never happened and start fresh?