What is he thinking?
Chuck: He is thinking, in the immortal words of Bobby Brown, "It's my perogative."
He's thinking that, despite the fact that he betrayed your trust by cheating on you with a married woman, and that you had a loud and angry breakup with him, it's been four months, and you'll still agree to roll around in the sheets with him again. Aaron is basically thinking that since all of that meant nothing to him, it should also mean nothing to you.
This is a crucial miscalculation men frequently make with women: They assume that women view sex as casually as they do. Some men can separate the emotional component from sex pretty easily, and just look on it as stress relief, recreation, what have you. Women, in most circumstances, need to feel something other than indifference or seething hatred for their sexual partners. That's just my opinion, but am I right?
You're not willing to put the past behind you for a booty call with this guy. And you shouldn't continue to get pressure from him to change your mind. State to him, as firmly as you can, that what he wants to happen isn't going to happen, and to leave you alone. If he doesn't get the message, change your number. Cut this guy out of your life.
GARLAND: I agree with Chuck.
This guys is doing nothing more than casting his line and seeing where the fish are biting. Sorry to use this kind of metaphor, but it is true. You are absolutely right in assuming that he doesn't want to get back with you, in the dating sense. He's looking for sex and he's assuming that he was good enough under the sheets (or on the floor, or on the kitchen table, or on the ugly green sofa in the basement) that you'd be willing to let him back in for some off-the-record lovin'.
Guys can have the uncommital sex with little to no problems. Most (not all) of you ladies can't. If you took a quick survey of 10 guys - 8 of them would probably tell you that they could have absolutely enjoyable sex with a woman that was mad at them or not speaking to them. This is sad, but it's true.
So, what is he thinking?
He's thinking that you may be just lonely enough and he was just good enough to warrant a late-nite invite to your place and your bed. There is nothing more to it. Nothing grand, no great scheme, no undercurrent of held back emotion - he's just testing the waters. If you want him to stop testing your water... threaten to drown him.