Language is mild: 'ass' appears in a text, and there's some vulgar British slang like 'knob' and 'piss off.' Teens at a party drink from plastic cups, but no one acts drunk.
One character tries to forcefully kiss another a third character pulls him off and shoves him away. In one scene, a boy who was a victim of bullying when classmates found out he was gay is depicted as a lonely figure while voices and written messages on the screen taunt him. But sexual content is mild and mainly confined to kisses and hand-holding. There's lots of emphasis on liking others: who has a crush on whom, who's texting whom, etc.
Since a romantic relationship is central to the plot, expect flirting, dating, and kissing. Parents need to know that Heartstopper is a romance between teen boys that's set in England and based on the webcomic and graphic novel series by Alice Oseman.
