Last he saw was her clothed torso, emanating some dark miasma, then he loses consciousness and wakes up naked in bed? Dunno man, I don't remember him giving her his consent to do anything. This poor guy got raped and by a ghost at that. (no doubt, swap the genders and it's clearly still rape)
At least he didn't die (yet) like those two girls in the first arc, but his life is in shambles. I wonder who'll send a damage report to Makube about this. This is a dangerous man-eating ghost on the loose.
This manga loves to give lessons to college students. The lesson this time is never go to a mixer if you're already in a relationship. This chapter is basically a supernatural allegory for getting roofied at a bar and waking up the morning after, realizing you were raped.