Yes they do dear. You don't want any poop to coming out during sex now wouldn't you? That's why being a bottom can be hard (no pun intended). Salutations to all bottoms out there!
Oooh.. Thank you.(⌒▽⌒)
in fact, they did not make the necessary preparations yet. That's why it's hurting like hell for the bottom
http://www.mangago.me/thing/about/17549/
An answer to all your questions.
In the end it's all about muscle contraction / muscle relaxation (the buttucks are our most prominent muscles after all) and various factors come into play in that departement: stress, consomption of psychoactive drug (including alcohol), experience, preparation, et cetera.
⁄(⁄ ⁄·⁄ω⁄·⁄ ⁄)⁄ Auhm... The "preparation" thing... In reality.. Does male to male couple do that? Aaah so embarassing... (￣ε(#￣)Σ