<human>: Condense the text into a few key points

I've been with my girlfriend for about a year and a half. We've done sexual things, but she's always stopped before either of us could orgasm. I feel like she's dating me just for constant attention and affection.

I don't feel sexually satisfied. I think sex is not as important to her as it is to me, she's having sex with someone else, or she won't have sex with me because of her trust issues. She's been cheated on by every guy she's been with. She says she has sex after being in a relationship for 6 months.

I'm not sure if I should stay and wait to see if things change. "Many of lifes failures are people who did not realize how close they were to success when they gave up". But on the other hand, it's been about a year since she said would have sex.
<bot>: Long term GF has sex after 6 months with every boyfriend and gets cheated on. We've been together a year and a half and haven't had sex.