Most Helpful Girl
Regardless of your state of mind or level of sobriety there is never an excuse for cheating. Love means that, regardless of whether or not you find other people attractive you would never ever dare do anything beyond the terms of your relationship with them. That also shows respect for the person you're with.
There's no excuse. If all it takes is you being drunk to forget that you love me and forget/stop caring that you promised to only physically be with me then that shows me just how little you care and respect me so I'm done.1