Hello,
Hair removal creams are a good way of removing unwanted hair.The concerned side effects is irritant contact dermatitis. Irritant dermatitis, the most common
type of contact dermatitis, involves inflammation resulting from contact with acids, alkaline materials such as soaps and detergents, cosmetics, or other chemicals.
If it happens,then take some antihistaminic like Benadryl and apply calamine lotion and steroid cream on the effected area. If the irritation persists then pls get it evaluated from a dermatologist.
Hope it helps.Take care and pls do keep me posted on how your boyfriend is doing or if you have any additional doubts.Kind regards.