He might be an 18 year old lad but if he behaves like a stupid one it's going to seriously affect his career. There's plenty of 18 year old footballers who wouldn't be unprofessional or dumb enough to bring random girls back to a hotel room on their first international call up, during a world pandemic.
Bissaka has no excuse. Maguire might have been unlucky but his story of what happened doesn't make much more sense than the police version of events, so you have to suspect there was a degree of stupidity involved.
If we want to be a bunch of mid table jokers who have to sack the manager every 2 years just to keep the asylum under control it's fine. If we're actually serious about wanting to challenge for major trophies then stuff like this shouldn't be happening, because the players shouldn't be prioritising random childish shite over their profession/ambitions.