The act of pleasuring people of considerable age difference to yourself

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

If something's terrible or bad or boring or just generally negative, it's 'waning'. Derived from the cycles of the moon. Opposite of waxing