@butterfly123 This is a rite of passage for a lot of teenagers (being cheated on). It’s not your place to get involved other than being supportive, a shoulder to cry on, an ear to listen, for your daughter.
What happens next will be interesting:
*The boy will possibly never cheat again, and he will call it a lesson learnt. (Which is exactly me 30 years ago at that age, I cheated on a girl I loved (also inebriated) and still feel bad about it to this day - I’ve never cheated on anyone since).
*The boy will cheat again, in which case it may be a lesson learnt for your daughter.
Teenage romances aren’t generally built to last, and your daughter will go through many more heart aches of this or different styles over the next decade or so.
Be the support pillar for her.
Make sure she can come talk if she wants to.
Don’t get involved, don’t even offer advice, unless she specifically asks. And even then, offer her options, let her decide her outcome.
Well that’s just my two cents. I was once that 14-yr old boy, but am now a 44-year old father of a daughter.