Colleague being cold with me now

We were friends and now he's completely giving me the cold shoulder. It's almost as if he goes out of his way to avoid me? I don't know what i did wrong. I asked him about it and his response was "just busy" which I know is BS because he talks to everyone besides me. It's very uncomfortable for me at work right now. My gut is telling me "who cares" but I do care at least to know why? Whatever the answer is will be but I hate cowardly people who can't even bring themselves to be honest with someone. PS.... we did have a few sexual encounters this past year... but we had both agreed that we would remain friends and that it wouldn't affect our work relationship but I think it has. Am I just a complete fool?? lol I must be... Thanks for any input that you may offer.

Ok. So you had a sexual relationship with a colleague. Dont worry!! It can happen!! We spend a lot of time with our co workers so sometimes feelings can arise. Yes, I do agree that if you can avoid the situation then do, as it could turn out awkward, just like the way it has for you. If I were you, I would avoid him too and see if you do get a reaction from him. If he cares, then eventually he will approach you but if for him, it was just a 'good' time, then he will not approach you and I guess you will have his cowardly answer. Hope things get better for you in the workplace. And with time I am sure this awkward/unpleasant phase will pass.