I agree how he treats the girls is objectionable, like the other guy said he could do way worse for zero sacrifice so at the very least when he's put his life up twice now that ought to count for something right? Well not according to the: "nice guys are only being nice to get into my pants...
I mean there's no way the original brother who's an actual 5yo or whatever would be taking care of his 2yo sister like our MC would as a 30yo or whatever. So that alone the sister is almost guaranteed to be saved and won't be jealous over some random.