Underwear is part of an ass spanking. There are different types of underwear for guys and men. Here are a few types which can be worn during a spanking and what they are good for.
Underwear during a spanking
After the normal pants (e.g. jeans or sweatpants) are taken off, you still wear underwear. Depending on which types of underwear are worn, spanking is possible in different ways. Besides, during an erotic spanking the right underwear can also make you horny.