Cannot relax on bed

This is driving me crazy so any help would be much appreciated.
Previously when I invited my sims boyfriend  over he would be able relax on the bed, make the bed, nap etc. However he moves in and suddenly becomes incapable of interacting with the bed other than to sleep. The option is available and when selected, he walks to the bed and the action disappears. Naturally, it has also been impossible to woohoo or try for a baby as the oaf just stands by the side of the bed and eventually walks off.

The relationship is high, the bed has been changed countless times and there is ample space around it, they have moved into a new house and the game has been updated.

I can't do anything else so it's most likely some sort of technical glitch! Help!