Is this a "guy thing"

So as a female, especially at the job I have, I get flirted with a lot. I don't think much of it and even if the guy is "attractive or sweet" I again don't think much of it bc I'm a married woman. But I feel like guys take being flirted with more seriously. But that's not really my point exactly. So I know when my husband sees or talks to a pretty girl bc he acts different. My ex did the same thing and this is random but on the queen of kings there is an episode I watched recently where Doug has "a thing" for a waitress he thinks likes him but he's happily married and Carrie is like wtf!? But it's not like a deal breaker or anything in their marriage bc it's just the feeling of being liked or flirted with is nice and I guess it's kind of like if you have a celebrity crush and you tell your spouse and it's not a big deal at all right? So I guess my question is... Do y'all go through that with your SO? My husband pretends like I don't notice when he acts different for a few days after being around a pretty female, but deep down we both know. And it's not cheating if nothing happens right? I guess sometimes I get discouraged bc I never think on it much if I see an attractive person but when my husband does it's like obvious he feels some type of way. We talked about it and he's like "it's a guy thing" what do y'all think??? He's always been loyal but there has been times in the past where he took it way seriously and we actually discussed getting a divorce around that time bc he was "bored." Of course we have grown since then but maybe bc of that and him saying "yeah I would find someone else" kinda stays rent free in my mind now. We have been through a lot of obstacles together and have gotten through them but I'm still pretty insecure even if it is harmless staring or something.