Well I suggest you ask your wife if you can invite your sister in law over for a girls Glam night! We have one on occasion here at home and invite friends that know about my Raven side. We all dress in evening wear maybe dinner definingly enjoy a few adult beverages to lighten the mood. Sometimes it has turned into a bit of a fashion show, you can show your wardrobe and I'm sure will be asked to model different outfits. We've never had a girls glam night that didn't include 2 or 3 wardrobe changes throughout the evening.

Just a thought if your wife is willing to indulge and you're willing to do a full disclosure to your SIL