i'm sorry if i'm being simple, but do you mean he was calling phone sex services? if so, HE called THEM, not vice versa. 15 year old guys are full of raging hormones and they think about sex constantly. sex isn't filthy, but it can be inappropriate. however, he initiated it and i bet he enjoyed it. it's not the phone company's fault. make him cough up the money. sounds like a summer job is in order.