What a load of balls. I swear LOTS in my personal life, not when I'm working, duh! And for God's sake, never bug a staff room if you think "tosser" is the worst thing a teacher can call a child! 😂
The point is, as other posters have said, you seem to be (as evidenced by the title of the thread) dismissing this as 'boys will be boys' sillyness which there is clearly no way for you to control, and hoping everyone will agree with you and tell you it will fix itself.
Plenty of people have pointed out that your child's behaviour will have had a negative impact on the children he targeted for his 'silly' comment. You don't seem to care. People have pointed out the impact of this kind of behaviour on their daughters - the desire to go to a single sex school for example, to get away from 'silly' boys who comment on their bodies.
As to the idea that I hate men, that's a bit of a stretch isnt it? I don't hate men as a sex class. But I do detest toxic male behaviour, not least shouting at women and girls on the street. OP's son is shouting comments at people about their genitalia. This is not ok and I don't think it's completely mad to associate him shouting "I can see your vagina" at some poor girl trying to get changed for swimming with blokes shouting "nice tits" out the window of their car at some poor girl / woman.
Do people imagine that those twatty men who go out of their way to target / intimidate/ harrass women didn't display any negative behaviours when they were children? Or that those groups of teenage boys you don't like to walk past were all perfectly behaved as pre-teens? At what age does the switch flip?
Behaviours and attitudes are engrained over years and years. In my experience, silly year 7 boys who act in the way that the OP has described were doing so in primary, amd continue to do so as they move up through school, but with the behaviour getting more extreme / inappropriate/ anti-social as they age so that they keep getting the reaction they want. But hey, again, one decade and 2,000+ pupils on which to base these observations, so, you know, I am clearly just talking out of my arse.