This issue has been resolved: Please update your game to 5.32 Downtown High School.
Sims will "refuse" to WooHoo in the Lofty Penthouse Penthouse bed.
What's causing this?
The bed that causes the problem is the White Delice Bed that comes with the Penthouse.
What can be done?
Try using another bed to WooHoo - in the meantime, the game team is investigating the problem to be corrected in the future.