Selena Gomez loves ''bad boys''.

The 20-year-old actress has had an on/off relationship with Justin Bieber for over two years and while some of her friends have urged the star to dump him for good, Selena can't let go because she is attracted to Justin's bad boy persona.

A source told ''Even though Selena is a good girl, she's attracted to bad boys. As much as all of Justin's acting out is a turn-off for her, there's also a part of her that's kind of excited by it because it's so different from how she is.''

Justin's latest indiscretion involved peeing in a mop bucket and shouting ''F**k Bill Clinton'' [the former President of the United States], a video of which leaked online this week.

Meanwhile, Selena's on/off relationship with the 19-year-old singer is costing her friendships as pals struggled to understand why she is with him.

The insider added: ''The whole situation with Selena and Justin going back and forth is costing her friendships.

''Every time Selena breaks up with Justin, she trash talks him to all her friends and gets everyone to join in. Then she ends up running back to him and it's just awkward for everyone.''