why is this guy acting weird?!??!?!!!!!?

[oodras]

This guy got my number from my friend. He took me on 2 dates and we would call eachother all the time and text for a month. After a month I went to a club with him and kissed him (I was kind of drunk). After that, he stopped contacting me. After a month of no contact I ran into him at a cafe and he bought me tea. We had small talk and he sarcastically said thanks for congratulating me on my Grad. To be honest I never did since we didnt talk in so long. Why is he acting weird ? Why would he even bother buying me tea if he won't talk to me? Also, I notice he added some of my friends onto his facebook....why would he do this? please answer!