Reminds me of the time City played at Blackpool in the FA Cup in 88.
Ended up in a pub on a side street off the sea front before the game with many of the Guvnors in there (didn't know they were in the crew at the time) and lots of singing going on. At one point we were all singing "Manchester la la la" and this lad stands in the middle of the floor, whips his jacket off to reveal a rag replica shirt and carries on singing as if "we're all in this together aren't we lads".
Next thing after a few cracks, he jumps over the bar for protection and the barman throws him back over..... more slaps... the bouncers came down the stairs and dragged him out. The room went very quiet and one blue says "who was with him?" And one lad goes very sheepish and stood out like a sore thumb with his stance and posture. A Blue went up to him. "Are you a M*****?"
"No"
"You sure?" and pulls this lads sweatshirt down from his neck to reveal a rag replica shirt. More slaps. The bouncers come down again and save this lad from a proper good hiding.
The bouncers then return. "Are there anymore United fans in here? This is your chance to leave with us now because we aren't coming down again". Two relieved rags shuffled quickly across the room to rounds of laughter and jeers.
To this day I still can't fathom out why the first rag thought it would be all peace, love and understanding when he decided to reveal his colours during that song - or why they were there to begin with!