I have 3 little kids ranging from 21 months to 5 yrs. We've go through this from time to time with all of them. I think that the less of a big deal you make it, the better the kids react and adjust. If it's not interfering with things we really need to do, we let that child have time with their preferred parent. The other parent just backs off for a little bit. Sometimes when my kids want dad, I'll say to them, "Have you got your daddy? Isn't daddy awesome? That's so fun." Just to let them know it's great to have time with that parent. If they're really wanting dad, but dad is needed elsewhere & we have to do the hand-off, we just say, "Daddy has to go now - bye-bye Daddy" and then without too much ceremony, we just hand them off. When they start to scream for dad, I just tell them that Daddy has to do whatever it is now & isn't that sad. Then I just try to distract them with something they love - snack, toy, whatever. Just try not to have dad hanging around where the child can see him & be reminded of what they want and can't have. Kids have a very short memory and are easily distracted. It's kind of like when you leave kids with a sitter & their heart breaks for 5-10 minutes, but then they're perfectly happy for the rest of the time. This has worked very well for us and I think that because we don't get excited about it and we acknowledge what the child wants, it hasn't become a huge problem. The kids have learned that it's okay to want what they want, but that doesn't mean they always get it. Good luck!