ex + best friend = together. Options

[sprezzatura]

I have broken up with my boyfriend of 2 weeks in the summer. Yes, it's a very short relationship, and I don't have feelings for him.

We used to be very good friends before we got together, but now it's drifting apart because of that. I know it's my fault for accepting him, but he did like me, after many times of rejection, I finally accepted him just to make him feel better, although I knew that I only treated him as a friend. YES, IT'S A HUGE MISTAKE. I regret for being so mean to him and breaking his heart. I have avoided him online and personally because of the grief.

When school started, I have history and English classes with him, I rarely talked to him in class despite how many times he had tried to strike up a conversation, I felt mean, but he was a jerk to me sometimes too. But generally, he's a good person. My best friend also had English class with me and him, and in fact she was a very good friend of my ex. I didn't talk to her much during class because usually my ex was there with her, but after school and online I did talk to her. Also, she was aware that he had liked me before.

During winter break, things started to get icky. Somehow my best friend and my ex got together. I was kind of expecting that because they were such good friends, but I have always thought my best friend would reject him (just because she didn't seem like the type that wanted a boyfriend, maybe I was wrong). Actually, I didn't find out they were together until a month later when we came back from school for several weeks already. I found out from my ex's AIM profile that read "I LOVE *NAME OF BEST FRIEND HERE* in Chinese."

I asked my best friend online if he really liked her or not, then she returned me with a comment "he had liked you too before." Then I didn't reply because I was away. When I came back from away, my ex messaged me and asked me homework questions. I helped him out then I was curious and asked him "Do you like *best friend's name*?" Then he told me that "We are a couple." I was so much in shock that I just came up with something lame, which was "Congrats!" Then I asked a few details about it too but I was being to nosy and I stopped asking them questions.

Yesterday I saw my best friend browsing through books in the library, because I was looking for sources for my research project in that same aisle too. Right after I walked past her in that aisle, my ex came and hugged her from behind and gave her a peck on the cheek (which he never did to me when we were together). I didn't know why, but I felt weird (sorry I didn't know how to describe my feelings) inside and I just walked away.

I have this feeling that I might be jealous of them, yet I do not have any feelings towards my ex (never ever, even when we were together). It might still be the grief that made me feel that way. I don't know why.

I was lost in this situation. I don't know if I am supposed to feel happy for them, or am I supposed to feel the other way? I don't know.