A Celtic fan blamed the break up of his relationship for hurling sectarian abuse at Rangers fans.
Conner McMillan shouted “You orange b*******s” at visiting supporters outside Celtic Park in March this year.
The 21 year-old Kilmarnock man made the remark in front of police before the match that the Scottish champions won 2-1.
Glasgow Sheriff Court heard McMillan had split up with his girlfriend of two years a few days before the match.
His lawyer Sat Singh said: “This was completely stupid and idiotic behaviour.
“It’s fair to say the build-up to the game was a difficult time for him as they had lived together. He moved into his grandmother’s house.
“He had been drinking that day before committing the offence.”
McMillan pleaded guilty to threatening and abusive behaviour to cause a reasonable person fear or alarm on Friday.
Sheriff Shona Gilroy deferred sentence until January next year for him to show good behaviour.
McMillan has already been banned by Celtic from attending games.
