Original Description:
Pinkie wets her swimsuit all the time - it’s meant to get wet anyway, so why bother? But pooping her swimsuit (while trying to fart) is much more unpleasant. But, being Pinkie, she shrugs/laughs it off and continues on with her day in her messy swimsuit as though nothing happened.
(Oh, like YOU’VE never soiled your swimsuit, Dashie…)