This is a few years late, but here goes. It's not the womb that's position can change, it's the cervix. In general, a women's cervix can be naturally higher or lower. This accounts for the different preferences in penis/dildo size, and also why a small contingency of women find almost any vaginal penetration uncomfortable. Sexual arousal and lifestyle changes can help raise the cervix, along with good health (particularly hormonal health). This is one (of many) reasons foreplay and the mantra "she cums first" are so beneficial to having good sex.
Well, I suppose this is why you never leave for week long trips like, ever, and if you do make sure you uh...Satisfy your wife first?
I must say though, props to the brother for at least...um, sort of resisting a little bit, even if it didn't amount to much in the end and things still progressed.
That ending though. Well hey, better to find out than to be strung along and kept in the dark I suppose. I'm actually curious as to what the husband might do with this knowledge actually, considering the...way in which he found out, literally catching them in the act. Divorce probably?
It'll go the void of nothingness. Even with the very, very few stories that has a plot that goes past where the victim finds out, it usually follows with absurdity, some of which thresholdofchaos listed.
It's hentai, husband is gonna be shocked sure but he'll either 1) admit he's been having an affair, they get divorced or, 2) it was his ultimate plan to be his brother's wingman (unlikely), 3) joins in the fun and they become one big happy family.
I'd love to hear other possible sequels. XD
Ah, too bad you made this couple years too early...Another possibility is the paramour threatens to beat the shit out of the husband and tells him watch and accept the defiling of the wife.