The 37-year-old dancer wed the 'Pretty Girls' hitmaker in 2004 before separating three years later, but said he originally felt he needed Justin's blessing when they first got together, as she had previously been in a relationship with the singer from 1999 to 2002.
He revealed: ''In the beginning when [Britney and I] first got together, it was awkward and I felt bad - I felt like maybe I should have called [Justin] and talked to him.''
Although he admitted he didn't get in touch with the former 'N Sync star because he ''didn't have his number,'' he insists they are on good terms nowadays as they have several mutual friends.
He said: ''We're cool. Me and J are. I actually just went to his last show in Vegas and hung out with him, got to see a lot of old friends.
''My best friend is his choreographer so we have mutual friends, and I mean, we've gone out golfing, we've hung out. You get older, you grow up, and you realise that was just a time in your life. S**t happens.''
The father-of-six - who has sons Sean Preston, nine, and Jayden James, eight, with Britney - also recounted his first romantic encounter with the 'Toxic' singer, who is currently dating Charlie Ebersol.
Speak to Us Weekly magazine, he recalled: ''I went out to a club, we just hit it off. It was weird. It was one of those things where, it just happened.
''I was just dancing on the dance floor and we kind of just had this chemistry...We both got very involved and interested in each other. And it just kind of took off from there.''
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