He treats me differently after he found out i have ?

Ok so im 18, and yes i have but its not like im a w h o r e, i do it responsibly and only with people i have had a deep relationship with, only 2 people. Im in senior in hs, and in my cooking cl we were talking about spermicide being in Cool-Whip, and some kid pointed out the ingredient, so i went to purse out of curiosity and discreetly where i had a condom to see if it was true, and the guy i was speaking with was mature about it and yea we had good laugh, but this other kid who was a freshman started to act all weird and annoying around me. Like he started acting flirtatious in the 12 year old sense. He would hit me with a plastic spoon and throw towels at me, and teasing me about the cool whip. Before he was shy and didn't really talk to me that much. Im pretty sure he knows that my bf broke up with me 2 weeks ago, and he just recently got rejected. What, does he think im automatically going to have with him now? Whats with him?