<human>: I (23F) met a wonderful girl (25F) around thanksgiving last year, and we've been dating ever since. She is sweet, very smart, and we have a lot of fun together. We've even started talking about moving in together when my lease is up. 

She's had a couple close friends she's known since college. They spend a good amount of time together, and some were roommates. However, I just recently learned that one of them (23M) gives my girlfriend full back massages periodically when they hang out. When I asked her about it she said that they've been doing it since college, and they've never been naked, but that they do strip to underwear (or at least she will, I didn't ask about him). She says she didn't mention it because it didn't occur to her, as its been a part of their friendship so long (they were roommates). I expressed that I was very uncomfortable with it, and asked her not to do it again, and she agreed.

I know she's dated men before, and that he's straight, but I have no idea if either she or he have ever had feelings. I want to believe her that they were just massages, but even then I'm feeling very angry. It feels dishonest that she didn't tell me, and frankly odd too--I can't imagine doing that with one of my friends, gay, straight, single or taken. I'm not sure if this is just insecurity cropping up on my end, or if I really should be concerned. I've never dated a bi girl before, too, so I'm not sure if there is some of that here. She agreed not to have him massage her any more, which is good, but I still feel hurt and jealous.

Can you give me a shortened version of the text?
<bot>: GF's long term friend and ex roommate was giving her back massages for years. Just found out, asked her to stop. Feeling hurt and betrayed. Was I?