Please use this thread going forward: [SD] [SE] Sims won't enter Sauna/Hot Tub/Hotspring for woohoo | EA Forums - 4956222
I am having the same problem. After I invite him to woohoo in the sauna, he heads to the sauna and cuddles up to me, but the woohoo is not executed and he leaves as if the action was cancelled.
Same problem occurs in the hot tub. However, it seems to work if you invite them to woohoo when they are both soaking in the hot tub.
The same problem occurs in the hot springs. Previously only teenagers had the problem, but now adults can't woohoo in hot springs either.
Now I know how to woohoo in a sauna or hot spring.
This may work well if you do not place other objects within 2 spaces of the sauna or hot spring.
This will allow all Young Adult and above Sims to use woohoo, but Teens will still be unable to use it.
