On this is pretty stupid for the reason of the boyfriend is practically non existent as well as the girl literally saying what she's doing is her true self. There is no reason then for her to care if her boyfriend finds out or not. Especially if she says that she'll marry the ntr guy if he makes her pregnant.
@vjbeal96 It seems that the girl uses the existence of a boyfriend to satisfy her sense of immorality and gain pleasure. This is just one of proclivities, not stupid.