A wife is permitted to wear revealing clothing for her husband, such as short, see-through, or tight garments that display or outline her body, and the same applies to the husband. Since it is permissible for spouses to see each other unclothed, wearing such clothes is not considered prohibited.

With regard to inserting the finger into the anus, this should not be done, for several reasons. With regard to simply touching the anal sphincter, there is nothing wrong with that, but it is better to avoid doing that because that may lead to something else.