Pfft, if you're doing it for the gals to have eye candy, we could care less about the package size. Make it an ass size slider and then we'll be on to something.
Girls like gigantic asses? Why was I not told this?
Guys have smaller butts than women because you don't have wide hips. Plus they're more muscular. That's the attractive part.
But if we're adding butt sliders, we'll need to talk about ab sliders as well.