That kid was probably bullshi**ing, you should have just grabbed his collar and put him against the wall and he would've shut up, the fact that he is 12 tells you a lot, he is just entering puberty so is probably excited (is that the right word) about sex and all that stuff.
You shouldn't take this guys comments serious however there are some people (older ones) that do have them 'one night stands', not saying it is wrong or anything but some people prefer that whereas some people just wanna 'look for that special someone'
Anyway those are my views