a sensation in your ass caused by heightened bloodflow and excessive pent up steam- akin to the feeling one gets when they pop a boner, but with your butt!
symptoms may include: emptiness, warmth in affected areas, back arching, bouncing, lust drunken thoughts, potential promiscuity, need, and- in extreme cases- vivid daydreams that bleed into sleepless nights.
if you are submissive and breedable enough to be familiar with such a condition, I suggest you be a good pet and find a way to let off that pent up steam. c:
I should sleep right now but this butt boner is telling me otherwise