also shit sorry forgot to add
it'l also the SHAPE of the penis
http://www.thepenismuseum.com/a-guide-to-the-penis
some shapes are great some shapes are just a pain... literally, yes there are ways to handle it, but certain sizes and certain shapes are just difficult to handle at all, but then again some are more fun,
i love blowing the mushroom because it gives the *pop* sound
but the bullet hurts especially when it's really long and really thin, it's like a needle stabbing into your cervix
the cut or uncut becomes a factor