“I wouldn’t want my kids to hang out as an equal with kids who think that is a fine way to talk. Clearly it’s the “logic” of his peers that it’s cool. Your son is probably trying to measure up to this little cliques lousy idea of etiquette.”
Although our kids are now grown, I completely agree with this.
Because of peer pressure, the OP presents a difficult situation. Often people say “They’ll grow out of it.” Sometimes that is true, sometimes it’s not. We’ve seen kids with these type of attitudes grow into adults no one (including employers) want to be around because of their attitude problems later in life, so it can be a real concern.
As we’ve seen with our kids and their peers, eventually, the realities of life will come into play, and lessons will be learned all around.