My ex (sons dad) got back with his daughters mom just days after us breaking up.. he's now thinking we are going to be…

My ex (sons dad) got back with his daughters mom just days after us breaking up.. he's now thinking we are going to be trading off every other week once he's born.. am I crazy to think it's not a great idea until he's one? I mean he's welcome to see him whenever and maybe some nights over night but not every other week until he's one.