Boku no Kokoro no Yabai Yatsu - Twitter comics by Fountains Square (Doujinshi) - Ch. 4 - Process of elimination

[MangaDex]

 

[Hollow7F]

do it

 

[bigtiddyoneesan]

Plot twist: the filled in parts are where she's not allowed to touch.

 

[Tamerlane]

She's forgotten the back side, which has particular orifice no man wants to be poked without mutual assurance...

 

[karzak]

Of course lmao

 

[Haydrion101]

Nani?!

 

[Takamita]

@Tamerlane I dunno man when you are into it and a sudden hand comes onto your behind it kinda is surprising at the beggining but it can be very ncie