What went wrong?
It’s hard enough to be in a marriage, and then have a kid, then kids, it changes everything. For me, I’d become more concerned with my children. Not that I ignored Britney, but my kids are always most important … I mean, we were having complications. I didn’t give her an ultimatum, but I was trying to work stuff out with her, and she didn’t even talk to me or anything and went behind my back and filed [for divorce]. [I was] completely blindsided.

Continued: Kevin Federline “tells all” in this week’s edition of PEOPLE.