What do I do

I M/37 have been dating a F/33 for 8 months. She has done many many disrespectful things along the way including giving another man a massage infront of me. Backstory on that one, I had been complaining of back pain for weeks with her not even offering a massage. On said weekend I spent the majority of it working on her car. Finally done Sunday night at 9:39 when I have work very early the next day, we’re in my sisters room with her friends and her kids we’re climbing on another guy for like 2 minutes. He said something about pain and IMMEDIATELY she pounced and said awww let me massage you and started to do so. I couldn’t believe my eyes and left before I did something stupid or even caused a scene. She saw no error in her behaviour. Said it was innocent.

Now present time, first I have to admit she is very attractive and gets hit on all day everyday. And on social media she gets friend requests by the many everyday. So yesterday she said to me oh I added about 250 guys from my requests lists because she made a bet at work that over 100 of them would message her. Actually she said that after, what she said first when I asked why is that she wanted to see the messed up things they would all say. Zero consideration for my feelings and complete and utter disrespect in my opinion. She brushed it off when I asked how would you feel if I added 250 girls. (Which she would be livid). How should I react to this? Like I said there’s many many cases of her saying or doing something along these lines leading to this point. Sex is great though which is huge in my decision. Do I put up with the constant torture of her disrespect for me just to have a hot gf?

TLDR my Gf has no shame and I’ve had enough