I have a few like this from time to time and it must be his age. He sounds like he's 2 to 2 1/2?
If you can try having him dressed before Mom comes to the door. Does she come close to the same time every night?

I had one today that was on and off challenging with her behaviour, throwing toys for attention, yelling at me for attention, then when Mom came she was just as challenging for her. The only good thing was at least her Mom go to see what I had to deal with. It does make you feel like the parents are wondering why is little Susie behaving like this?

It's so hard on them to be away from there parents that all those bottled up emotions come rushing out when they see their mom's.