What are his naps like (no I'm not stalking you this evening, honestly
)?
I have a technique I use with ds when he does this (not very often, but it's really annoying when he does).
If he screams when I leave the side of the cot, but wants to play when I'm there, then I'll stay, but I'll pretend to go to sleep myself. I know it sounds bonkers, but honestly, it works
.
Firstly I'll sit by the cot, tell him in a calm voice that it's time for sleep now, then I'll close my eyes. After a while, I'll move to a lying position. You have to be really strict with yourself here, b/c ds will do anything to get my attention. He jumps about, he giggles, he talks, you get the picture. I even had to start putting about 3 dummies in his cot b/c he learnt that if he threw it at my head
, I'd have to give it back to him. Basically, you do not react to anything except if he gets upset, then it's just a quiet reassure that you are still there, but it's sleepy time.
This does work, but it will take time, especially the first few times. I've been on the nursery floor for anything up to 1-2 hours, but safe in the knowledge that it will work.
Tell us what his naps are like, too - this could be linked.