To put the bottom half of your dick in a woman's vagina with either, cum, vaginal juice, or condiments

A jack off buddy (from 'cum' /'come', meaning 'semen', and 'companion'); a friend that you get together with for sessions of solo or mutual masturbation
Variant of: cumpanion (from 'companion' & 'cum'); jack off buddy & wank bud & JO buddy
Similar to: fuck buddy

a new york sub is when you spread the woman's pussy lips and take a big ol' steaming shit in her cunt... then you proceed to fuck it...