I love the idea of buttplug leashes! Do you have any extra lined up master?

Those are pretty rare in porn and real life, but they do make an appearance (chained to a cock ring) in Kinky College: Surprise Anal Sex Week chapter 11: http://www.asstr.org/~Broken_Arrow/2014/04/15-kinky-college-11—surprise-anal-sex-week-part-11/