Quote Originally Posted by Dododecapod
Actually, the rectum is quite pliable and remarkably tough. Which isn't to say you shouldn't take care...

The only penetration toy I've ever used as a punishment was a long, thin dildo with long, rubber fibres extending from the top. Anally inserted, it tickles the inner membranes fiercely - especially when coupled with a powerful vibrator.

My previous sub would be gasping for relief in under five minutes....

where can one acquire such a fascinating toy?