Boy trouble: What does this mean?

ok this guy which i'm still not to sure i like, does this weird thing when he "annoys" me, what ever pen i'm writing with he grabs it, and rubs it on one of his many scabs, ew, but the thing is i let him keep the pen cos i aint gonna touch that but he normally write with one of the pen's i let him keep, we traded the actual pen colour (the one i gave him was black and at the time i was writing with a black pen of the same type) and the end of the pen, and he keeps bringing up that it was MY pen in the first place, does this mean anything?