I'm trying to get in a FWB relationship with my ex. We ended on good terms, purely due to logistics (her moving to another state for work). A year later she's back but feelings have changed a bit. There's no connection, at least not in the same way as it used to be. I want to get into a FWB type relationship with her, which is how we originally started before we were a couple. So we hang out and have sex maybe 5 times in the past 2 months. Then she tells me she wants a break from me. Not from hanging out, but from being a couple and having sex. I tell her I'm fine with this. We still hang out and have sex maybe 2-3 more times, usually but not always initiated by me. She then tells me again she doesn't want to have sex with me.
Then one night we hang out. We go drinking then plan to go "chill" at her place. We get there and she tells me she doesn't want me to come in or continue the hangout because she knows I'm going to try to fuck her. We get in a pretty big argument but she called me the next day to apologize, saying she's on her period and has been really emotional lately. Then we hang out one more time since. We watch movies at my place but after the argument that just took place I don't make any move on her. She cuddles with me all night then ends up sleeping over (we smoked a bit of pot so she didn't want to drive). I wanted to make a move. So badly. But I restrained myself. I didn't even press my boner against her ass like I normally would with any other girl I'm cuddling with in bed. If I did make a move, I would be proving her point behind the argument losing her trust. I feel this would cause more damage then good and even though I would probably get sex that night, it probably wouldn't happen again.
Now here's the deal. I want to have sex with her. When we have sex, we have great sex. It's always really really good sex. She tells me I'm the best she's ever had. And she's a freak in bed. I just don't know how long I should wait before I should initiate it. How should I set up the night? I feel like if I make a move and she's not into it, it could end really really badly. What do you think?