Tempted to Cheat

Ladies, for the first time in my decade long relationship I am tempted to cheat. 
I have to say, I will NEVER cheat. I would never act in any way on these thoughts. However, a man recently expressed interest in me. I turned him down (of course), my husband knows all about it and completely trusts me and knows nothing happened. 
I can't get the whole thing out of my head though. I don't even care about the specific guy, it's just the temptation to feel wanted and desired. I'm tempted by the butterflies and the newness, not this guy himself.
I am not in contact at all with this man, so like I said this will Never actually happen.
I love my husband, he's my best friend and I would be Devastated to find out he's having these thought about another woman. I know I respect him enough to break up with him if I ever seriously found myself wanting another man but I hate this feeling. I honestly haven't even looked at another man since we've been together. I've never faced any type of temptation in our marriage (or any relationship), so this just feels awful.
Any relationship advice? Also, please no negativity. I would never cheat (in any way) and love him so much but have admittedly been feeling under appreciated. I don't have a lot of people to talk this over with so I'm just looking for some thoughts and advice.
Sorry for the novel! And I apologize for having to be anonymous, I have friends on this app.