All Grown Up (2003)

With Stu and Didi away at an Invention Convention, Dil wants to host a viewing party for a "real" alien autopsy video with Tommy. But when both Grandpa Lou and Grandpa Boris show up to babysit the kids, they all start to have a feud. This gets even more difficult when Phil, Lil, and Chuckie show up and Dil invites 10 other kids to come see it, much to Tommy's frustration.