At first i thought Onii-chan was forcing Meiko-chan to do all this but it turns out these two are just a twisted pair and honestly are both fucking nuts.
The second session, with the 2 guys, seemed unexpected and essentially a spontaneous rape. She didn't invite them, right? Am I reading correctly? They enter the stall supposedly following a smell (in a public toilet?!?) discover her in the lingerie and BOOM, they're in the mix. Everything she says no to they do, there is no indication that they are previously acquainted and whereas the first sex with the old guy seemed staged the second seemed random and unexpected. Or was This entire setup about sex with any strangers (plural) passing through this particular toilet this particular day...? Brother didn't fuck the sister but what he did do seemed (to my sensibilities) WORSE! Is it his kink or hers...? Or is it shared, him wanting to watch as much or more than she wants to be watched and "used"...? Also them peeing on her at the end made the entire thing more grimy and the water hose bloating her belly was just a weird cherry on top. Oh well, I guess all Minato's stories can't be expected to be homeruns...