Sources reveal that it may be hard for Justin to change cheating his ways — and that he still has a ‘wandering eye.’

Justin Timberlake and Jessica Biel are well on their way to tying the knot. But should Jessica really be walking down an aisle with Justin who has a history of cheating? Sources reveal that even though Justin claims to have changed, Jessica should still be on guard.

“Everybody knows Justin has a wandering eye, and Jess knows too,” a source close to Jessica tells Us magazine. “There is no way Jessica will deal with his straying eye now that they’re engaged. You are ging to see some changes from Justin.”

Yet, an insider close to Justin claims that Justin hasn’t changed. “Justin really loves Jessica, but he just can’t stay monogamous,” explains the insider. “His brain and his penis operate separately, and the brain proposed to her. He thinks it is what he wants, but he has two sides — and the other will pop back up. He has a big sexual appetite.”

Justin’s friends don’t help the situation. “He’s surrounded by a bunch of people who would do anything to stay in his good graces,” says another source. “They’re so afraid of being booted out of the circle, they’ll hide all his secrets.”

But Jessica supposedly has a way of keeping Justin on track. “She knows she’s going to have to limit the amount of time that Justin spends with his clubbing friends,” shares an insider.

Still, people close to the couple worry that he may just “be more strategic about his affairs.”

BFFs — should Jessica be concerned that Justin may cheat on her?

More Justin Timberlake News:

1. Justin Timberlake & Jessica Biel Engaged
2. Justin Timberlake Goes To The Marine Corps Ball
3. Justin Timberlake & Jessica Biel’s Major PDA At Premiere Party!