Barton opened the scoring for the Magpies with an excellent effort at St James' Park and after celebrating with his team-mates raised his right hand to his lip and his left arm straight up in the air.
However, Barton says he was merely highlighting the fact that with Newcastle on the way to their first Premier League victory of the season, he was expecting to shave off his moustache.
"I was merely pointing out that the moustache was going to go after the game," Barton said.
"I'll be shaving the moustache off now that we have won. There are a few of the lads desperate to get it off. It is either the end of my moustache or the end of my relationship, so I'm glad it is going."
Barton has repeatedly attracted controversy during a chequered career but manager Chris Hughton said he was unaware of the latest row to surround his midfielder.
"I can't clear anything up because it is the first I have heard about this," Hughton said. "This is about Newcastle United scoring six goals at home and all our concentrations are on that and enjoying a good game.
"Right at this particular moment I only see one thing and that is a performance he has shown us on the pitch and he was excellent. I am not in a position to say anything because this is the first I know of it.
"He is a very good footballer but unfortunately for us over the last few seasons with injuries he has not been able to be on the pitch as much as we would like. A fit Joey Barton is always an asset to us."