A kiss in the corner of your mouth
Theme date: October 14, 2007.
Their first time had been an experiment. Mutou had been drunk enough to be crazy but sober enough to be curious; Hasegawa had been drunk enough to be relaxed but sober enough to not go postal on the first living creature that interested her. They both stepped out of the experience kind of liking it, and from that point on they were comfortable enough with each other to walk around each other's apartments naked when they were lazy to wear anything at all in the summer heat.
Their second time had been an accident. Mutou had stumbled into Hasegawa's apartment, breathless and desperate, whining about taking some weird thing in Itsuki-sensei's laboratories and it might have been an aphrodisiac because she desperately needed to get laid by somebody. Hasegawa liked to think that she didn't really have a say in the matter, and had only acted as a friend would act by fucking Mutou senseless.
Their third time was intentional, and it wouldn't, after all, end up being their last.