Me & my fianc are experiencing a red burning itchy scaling rash. me on my butt & in the lining of the cheeks. him on his inner thighs & stomach?

Contact allergy?: May be a contact allergy that could be cause by laundry soap or other additive if you both use the same washing machine for clothes and sheets. Could possibly be bed bugs as well. Best to have your primary care examine the rash, and may need referral to a dermatologist. In the mean time, try to figure out what common environmental exposure you both have, and do some trial and error changes.