Fuck buddy confusing behavior?

So me and this guy I know have this casual fuck buddy thing going on. The sex is great, but what confuses me a lot is his behavior. Like both before and after he does a bit of cuddling, which is nice, but surprised me a bit the first time he did it, and is also so nice and personable, talks to me about all sorts of things... but like outside of his house (he lives alone so that's where we hook up) he's still friendly, but not overly so. Like he doesn't talk my ear off, doesn't seem to relax as much. And even though everyone knows we're fucking, he seems embarrassed about it. Is this normal? I've never been in a sex only relationship, so I wasn't sure.
Fuck buddy confusing behavior?
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