Why get one when you can get two?
As far as we know, she might as well aim for both siblings.
Now that's what I call an ending. Everyone's wins, nobody lose, everyone is happy. It's all win-win! Hurray for Harem end!
I come not for the plot but for the "plot"
But seriously, this author really has something against women pissing themselves. Or it maybe just his fetish.