How to ask my ex to have sex with me?

It's a bit complicated ... but here goes the fun story.. My ex was straight when i first met her. We dated 2 months , things started to get complicated the same night when she was at my place telling me that her ex male boyfriend want to see her and when i've told her that maybe i still have feelings for my ex and that we are still in contact! Anyways we agreed to spend the night together and after that being friends! I was working in the store where she was manager of the store. We were in touch , seeing each other at work , after work .. i can say that the feelings the chemistry were still there between us. I quit my job for other reasons and on my last day at work we agreed to spend some time together after work as friends of course and we went in the park where was our first date. We've talked had great time, she told me that we'll keep in touch , make her proud .. bla bla.. and three weeks after this friendly date she deleted me from Facebook and unfollowed me from Instagram! I asked her of course and her response was like she will feel better if we don't stay in contact she want to quit with this part of her life also that she has boyfriend now and that's it... My point is that i know she still likes me and try to protect herself from me she is 28 and was straight her whole life but i can't get her out of my mind and i really want to sleep with her again. How to ask her??? (Sorry for the long paragraph and my English) Any advice would be helpful . Thanks