A moment of pure stupidity. The term was first coined by the amazing and idiotic Twitch streamer Vargskelethor(Joel) from vinesauce during his second Black Mesa stream.
Wow, that soldierjust ran up to me, only to endure CBT. What a Mug Moment.
Any remarkable moment that might occur if and when you are drinking a lot of MUG brand Root Beer. The one with the funny dog.
"Damn, I really love MUG" - Jack
"Really? I don't particularly enjoy it." - Zach
"No, bro!" - Mr. Boner *in the process of clobbering Zach*
"MUG Moment!" - God, probably