Ah yes, you really can't trust them when they promise they'll 'pull out', because clearly they won't.
That ending though. Why yes, her brother-in-law someday, eh? Honestly, I'd think they get along...just fine. So much that your sister might get pregnant before you, eh?
Whoa...Unless she's lucky, this whole cheating session will end up exploding like an atom bomb, unless she wants to mother a kid without the open support a father (and he doesn't seem like the person who will take any sort of responsibility)...or she can trap some unfortunate dude into thinking its his (kinda seems a good possibly considering her lack of good character)..or I guess an abortion is on the table, which would be unfortunate IMO. Not really sure what was popping thru his head to make him decide to go bareback on somebody other than his fiancé or soon-to-be fiancé. Gotta love hentai logic.
DON'T YOU BELIEVE IT!