When I see lack of stamina or a drop in submissive response, I often explore options to keep things interesting. I'm dealing with that now my one of my subs, and I like to increase his frustration and up his service standards with me. I've asked him to consult his doctor to undergo checks and seek to obtain a rx for sildenafil, which he did and just got filled. Needless to say, that visit (aside from cleanings) was a rare occasion where he enjoyed a temporary unlocked status from his Lori #9... and, that I intend to use the sildenafil (Viagra) for teasing occasions and other scenarios whenever I wish. I'm curious about experiences regarding the use of sildenafil on locked males that others may have had. Thanks.