It seems that both of you are having tinea cruris
.it is a fungal infection
caused by dermatophytes. It is a contagious skin disease and spread by direct contact and fomites. Blood tests may be done to rule out DM and HIV. It may be exacerbated by poor immunity,sweating,soap and wetness. Dry the area after bath.
Both of you take antifungal drug like ketoconazole or itraconazole for 2 to 3 weeks. Take antihistaminics like levocetirizine
till itch is relieved. And apply anti fungal cream like clotrimazole
. Sprinkle clotrimazole powder after bath.
Avoid soap bath. You may use dettol liquid for bath.
I think, both of you may be alright, but, consult dermatologist
I hope you got my answer.
Dr. Ilyas Patel MD