Boyfriend has feelings for ex? Break?

My boyfriend has feelings for his ex and we've decided to go on a break because it was either that or he wanted to break up. We've been having problems in our relationship, and so has she, and they've started to lean on each other.

We decided that in our break, we could mess around with other people. I'm okay with this because I have some sh*t going on with an ex of mine too but, the difference is, my heart always was with my boyfriend, and his wasn't. He said he was torn between the two of us.

Now, a few general details.

I'm from the same friend group as him and his ex. Me and his ex used to be best friends.

Their relationship was absolutely the most toxic thing I have ever seen.

My best friend is great friends with his ex and she said shes going to kick her *** for all this today.

He said that even though all this was going on that he was still going to send me good morning messages, and that wouldn't change. (What does that mean?)

My question is what do I do. Will he come back to me after he realizes how bad she is for him, even with the problems that we've been having? Why is he going to send me good morning texts if he's going to go screw around with his ex? Also, should I reply to the texts? Is it a good idea for my bestie to kick the ex's *ss.? I'm so lost, please help.