in realtion to the MC and his demon powers, they obviously have only been unlocked when the nightmares started, which is like what, a week or so before MC starts getting lewd with every woman in the house?(figure his first memory of the nightmare was same day they said Lisa's birthday was in a few days and he messed with both sisters before making out with the mom on her birthday) the girl in the coffee shop was a virgin, banged right there on the floor behind the counter during working hours, and her bestie was the one who was trying to get with him, also nearly banged him in the bathroom until interupted.
idk, for me it makes sense the MC didnt bang the girls he lived with until the powers woke up. even if they were all into each other, which it looks like they were. they were adoptive family and took the MC in when he was maybe 4, he has zero memories of anything prior to that family. the youngest girl was born after he was taken into the family and they are adult age now. the taboo and stigma likely kept even the eldest sister away, and her restraint and frustration is likely what drove her to work in a sex shop. even with that being an assumption it a fair one, as much as it is quite normal to have sex with people who are not the one you really want, when you feel you can never have them. especially when you are all pent up living with them. look at how many people fall in love with a friend and keep screwing everyone else, half the time just to keep themselves from ruining the friendship by trying to date.
yes from the outside its so easy to say, well thats stupid just be together fuck what anyone else thinks. but thats not how people actually behave. if you wanna fuck your sister but society wont let you and suddenly demon blood awakens and makes you and her just not give a flying fuck, you are likely going to find out your sister banged at least one guy trying to get over not being with you. emotional people do stupid shit to protect their hearts, often shit people find skanky. but MC aint no virgin either, so wasnt like he was saving himself for the women at home either.
