Onna Kyoushi wa Mou Gaman Dekinai

The protagonist was stalking a female student that caught his interest. That was when Shijou Megumi, a teacher, intervened. Hoping to put the stalking to a stop, she suggested take her place, under the condition that the stalking stopped. If it were for the sake of her dear student, she'd put up with any embarassment, but their acts gradually escalated... Eventually, Megumi found herself unable to hold back any longer!