Ideas
+59
Personal Bests: Helping subjects achieve difficult sexual feats
Helping subjects achieve certain feats with your equipment. As in, produce some amount of semen, or shoot some distance, or endure some minutes of post-orgasm rubbing. Encourages experimenting with the equipment you've got to maximize whatever measurement they're going for. Could be open-ended improvement.
Customer support service by UserEcho
Additional suggestions: Self suck, paint the ceiling, orgasm for an excessive amount of time (or without end,) larger or smaller size, cock modification - make a non-canine species grow a knot (or even a canine gain equine features,) lactation, gushing.