I was checking volume 19 and Alibaba’s expression in this panel caught my attention again:

For years, I didn’t think much of Alibaba’s sweat-dropping. I thought he was just nervous or worried that Kougyoku was being friendly with him in front of her protective and scary brother. However, this time, I recalled a backstage in which Aladdin was running away from Alibaba in djinn equip mode because if he touched him, he will get burned. My new interpretation is that Alibaba became worried when Kougyoku touched him because his skin while in djinn equip mode will burn her hand. Also, in volume 30 omake paper Kougyoku described his djinn equip that it was hot (to the point it burned her). 

Pic from volume 19 Viz edition.