That is a lot of story. Kudos for cramming it into our limited text box.
Okay, so let's sort this out. First, I need you to take a moment and find your inner Yoda. That's right. Let's calm down and find a little peace. Visualize that deep inside yourself is a serene, knee-high, lizard-green senior citizen with magical powers. Actually, stop that. That's just creepy.
Here we go: is he into you? Yes. You two were having casual sex for ten months. Silly sexual affairs don't last that long, unless there is some underlying attraction there. Some kind of connection besides an excellent physical fit.
Relationships can sometimes just happen. Two people meet at a party, have a little too much to drink, and then one stays the night and then every night for a week. When two people relate in any way, you can say they are in a relationship. But romantic relationships can break hearts, and broken hearts have sharp edges. So that's why it's always smart to define your boundaries and set some ground rules.
This conversation cannot happen in the head of one person. It must be communicated out loud, in the simplest terms possible. I'm assuming both you and this dude both knew you were in a "casual sex relationship?" Yes? If those were the rules, then he technically didn't do anything wrong. He didn't have a fling. The two of you weren't not in a committed relationship. It was douche-y, sure. But the relationship wasn't serious.
Also: you told him it was over, but asked him if he wanted it to be over. You can't do both. You either bail or you don't. He's probably in shock. Or he's being a sly creep and thinking about how to have both you and this other chick.
Then there's the other point of view. That the both of you totally just skipped over the entire conversation where you sat down and had a talk. The talk where you go "I want to be with you and you only. Do you want to be with me and me only?" And then he either says "Yes" and the two of you go from "casual" to "not so casual." Or he says "No," and you say "LATER."
Oh, friends with benefits... le sigh. Been there; done that. he worst is when you are with someone in a "casual sexual relationship" for 2 years - you know nothing more will come of it and you go out with a mutual friend, since it makes more sense. First guy gets really mad and they cut you both off. It was always clear there was nothing to come of the first guy beyond sex, so then you are left wondering what the heck happened.
Totally agree with the response and the comment above. Funny though-I ended up in quite the similar situation as the commentor...only difference is after the 1st guy cut me off, he came back and we didnt even talk about it again...just became friends (i swear we only screwed one more time...for ol times sake)
I agree with everything that you wrote, except for the "you said it was over, then asked him if he wanted it to be" but she had asked him "if it was over jus tell me". Now had you of read it correctly, then I have no doubt that I would agree with your answer on it haha.
I'm kinda going through the same thing. Like John said, you have to establish exactly where you stand. The lady that I'm seing has agreed that it is only "casual sex relationship" but that we'd prefer that we only "casually sex up" each other. (it's a dangerous world out there, haha you can never be to save).