Once a cheat always a cheat?

So when I was freshly postpartum my partner was attempting to hook up with a woman from work, probably did. I found all the dirty messages, we had it out. Decided to work on things for our children. Fast forward and he tells me that he's going to be working 7:30 am -10pm most of the week. First red flag. Now tonight he's messaged that he's probably going to stay the night at work 🤔 his place of work is locked up at night and I'm pretty sure his bosses wouldn't be asking him to stay the night either. He's obviously cheating right?? I wanted to break up the first time around he didn't 🙃