Honestly, was he or she or both flirting or was it innocent & I over reacted?

My wife & I seem to always meet up with this guy at gatherings we attend. It seems like he always smiles and tries to engage my wife in conversation. We ran into him at a wedding and my wife kept making excuses to leave our table. Either to get a piece of cake or ladies room. If I follow her or look over, there they were smiling and talking. He even worked his way to our table and sat next to her and picked up a conversation. Occassionally looking over to me as if including me in conversation. Till it was becoming obvious that I wasn't. Then he returns back to his table. At the end of the evening, my wife worked her way near his table while he worked his way near ours. He smiles and says his departure greetings to her then plants a kiss on her cheek. He never says anything to me before starting to leave. I finally went to him (and not in a nice tone) asked him to stay away and never to speak to her again. I also told my wife the same thing in front of him. Btw, no one was drinking.

This sounds like a scene from an old movie...have you been watching too many old flicks? If it's on the up and up, you have a wife that is just before cheating, if she hasn't already.

GOOD FOR YOU!!
It's easy to see that this dawg was trying to pee in your territory!! Good way to try and stop him, but will it??

There is more to this than your seeing. You know this, don't you?? You need to do some "investigating". If and when you find your wife is cheating, pack her belongings and change the locks and tell her to leave until she can grow up, be a responsible adult and wife!!

Their seeing each other!

sounds a bit odd to me. they could just be good friends and he doesn't know you well and that's why he wasn't talking to you much. i give my male friends 2 kisses every time we see each other for hello and goodbye (but i also grew up in Spain and it is the custom) but i think they do this to friends in English countries also. i would ask her straight why she was paying so much attention to him. thing is if he was one of my friends i would not make excuses to speak to him, i would clearly say to my fiancee "hey im just going over to speak to Ben for a bit" her making excuses to then go over to the guy is what makes it suspicious. like she has something to hide. sorry.