A guy called me a slut then a poser?

So I was at my friends house yesterday and she was talking to the guy she liked and he likes her back, but then we were goofing off and i said to him, "I wuv you!!" and then she told him it was me. Then he was like can i talk to her? and she was like yeah. The he said, "Go find your own f***** guy and start loving him." Then he said, " F*** You! Your such a F****** slut and aa poser." Then i said, " What exactly im a posing?" "Ke$ha" What the heck!?? I am not a slut i am still a virgin, never even kissed a guy, and never had a boyfriend. Also i don't dress inappropriately i wear off the shoulder loose tops but still wear a one inch tank top underneath. I wore short shorts once since it was the end of school and the girl he likes also wore the same. And then I said to him, " Its going to be tough getting the girl if you are mean to her friends." (He also cusses out my other friend and calls her a B*** and stuff) Then he said, "Well your not a good friend at all so can you just shut up and can I talk to ******?" (names changed) Then as soon as my friend tells him its not nice to make fun of my friends hes all like im so sorry my gurl!!! I dont get why she likes him, i would never like a guy he cusses and btches at my friends. What should i do? Were only in 8th grade so of course i wouldn't be sleeping around. I think he may be using her for sex but i could never tell her that. Should i just let things go there course? Hes really pissing me off and i blocked him but hes like an angel to my friend. argghhh