PS Sammy can walk without underwear with really low Confidence until she goes into the Wardrobe. So there's no reason to press that Wardrobe button icidentally sometimes in order not to break current settings of the clothes.
I'll have a look into it. Once Sammy says it's ok to go without pants, you should always be able to go commando from that point onwards even if your confidence drops. Might be a bug preventing that.