I didn't use the spiked mat here, but that's another nice idea. Too bad my motion sensing e-stim box doesn't work in reverse...or I could REQUIRE the sub to move constantly in order to avoid his cock being shocked. If his feet were on the spiked mat, moving around constantly would be quite a challenge. Torture your own feet, or torture your own cock, those would be his choices at that point...all while I'm kicking back in a chair and watching the show. ;-)