Skinny chicks take turns jumping on dick in group sex

While a guy near the pool shows off his figure to others, two girls who came here to relax are having lesbian sex right in front of the guy. Naturally, he wants to join, and the girls themselves don’t see anything wrong with banging two people at once. Well, what’s wrong with this method of entertainment in the form of group sex, because it does no harm to anyone other than pleasure?