Should I end it?

So the boy I’m with (we’re both 15) is dealing with a lot of stress and has started to turn to alcohol (UK you can drink when you’re 18)

Today he promised me he wouldn’t but got drunk at school behind my back when I trusted him not to

He’s drank three times in the space of a week despite me asking him to come and talk to me if things are getting on top of him

This isn’t the first time he’s gone against my trust not just with things like this

And he’s begging me not to end it but he didn’t think about the consequences of his actions until it was too late

To conclude he’s been caught and may be getting excluded

Help