My ex broke up with me 3 months ago. We had texting back and forth in the last week. She started talking about sex and what we used to get up to and that she was really horny today of I said come round but she was like I don't think that's a good idea. She said that it had been ages since she had some and for some reason I asked if she had slept with someone since the brake up. She said yes and that she thought it might make her get over us but the theory isn't that also said that no one will ever be as good as me and didn't like idea of me with someone else.

Is she playing games? Missing the sex and me?

Can I ask why you both had a break up on the first place?? Was she cheating on you? Or were you cheating on her? Or was there any other reason for the break up? Right now how much I can understand from this is she misses you and want to fill your space in her life and I don`t think emotionally she wants you back but as for now she misses you just for sex... so just give things and your friendship some more time take things slowly with her if she comes backs to you emotionally than its fine to go ahead with it... but if she is just missing the sex part of the relationship and only texting you about how good you were in bed with her and all how she misses all that than she is just playing games with you. So if you still love her than don`t fall in that trap. Because it will only hurt you emotionally.

Do yourself a favor and end ALL contact with her until there is no chance of confusion and both of you have healed and moved on. Don't get together just for sex (if that is what she is wanting). Since NO form of birth control is 100%, it is not a good idea to tempt nature and Fate.

She can't play games with you if you don't allow her on the playground.

She is amusing herself at your expense, so stop the contact and avoid the head games.