"I'm used to not having all my kids, and this is gonna be one of those years," Federline said in the interview, which was published Friday. "When you are co-parenting, you have to be willing to give up some of the things you would really like to do. My boys will be gone, their mom's off in Asia on tour. They are with me until the 15th, and then they are gone for the rest of the month. So I won't have the boys for Father's Day. I'm doing a vacation with some of the kids and my nephew."