if she told you you were her only, then yes you should be upset and leave her. she took her sexual temporary wants over life as a whole. her loss.
if you are more progressive. then who cares? if you truly love your wife, thats even cooler a guy was able to fuck her and make her feel amazing. its not a knock on you. its okay.
“Yeah, we had a fun holiday work party, pretty normal. We didnt go that crazy.” - To their husbands/bfs when arriving home at 3am with tossled hair.