Is it bad to break up/take a break to sleep with other people?

My bf and I are doing long distance and he recently made a big deal over an argument. It didn’t seem like it was that big of deal but he said he wanted a break.

Now I found out that he’s sleeping with people (I know for sure and have proof) so it looks like to me that he made a big deal over a small argument just so he could ask for a break and sleep with other people without the guilt.

Is it crazy for me to feel like I understand that long distance is hard and it’s understandable that he would crave sex? I wouldn’t and can’t have sex with other people myself, just wouldn’t be able to, but I kind of get him.