Selena Gomez 'disgusted' by Bieber's behaviour

Selena Gomez was apparently "disgusted" by Justin Bieber's mop bucket incident.

The two stars have enjoyed an on/off relationship since 2011 and are currently rumoured to be back together.

Recently a video emerged of Justin urinating into cleaning equipment in the kitchen of a New York club before spraying a picture of former US President Bill Clinton with detergent and saying: "F**k Bill Clinton."

The stunt reportedly didn't go down well with the pretty brunette.

"Selena was disgusted when she heard what he did in the club," a source claimed to British magazine Star.

"He has sworn if she gives him one last chance he won't let her down."

The pair first sparked rumours they were back together when Justin posted a picture of himself with the Spring Breakers star after the Fourth of July holiday.

TMZ later claimed they had made up - but with strict conditions Justin improve his behaviour.

He's been accused of speeding around in his Ferrari as well as smoking marijuana and assaulting a neighbour.

"Selena has told Justin that the speeding, turning up late [to concerts] and arguing with paps all have to end if they are going to work," the insider continued.

Justin apologised to Bill following the emergence of the tape, with the politician advising him to pick his friends carefully.

Sources are sure Selena is a good choice of company to keep for the 19-year-old.

"When Justin is with Selena, he seems calmer and more focused," the source explained.

"She keeps him grounded and is the best thing for him. Everyone is hoping this time Justin will actually listen to her - because if he pulls another stint like this bucket incident again, she won't stick around."