forced milking 

When you tie up a guy and jack him off repeatedly without stopping. After he cums a couple times, he'll become overly sensitive, and continuing to jack him is pretty intense overstimulation, so the body's natural reaction is to move away. That's why it's important to tie him down first.

Usually found in bdsm encounters.

"forced" distinguishes it from other things that are also called milking.

milking forced milking

forced milking by d43 March 4, 2009

Forced Milking 

When a guy (or girl) is tied up, a naked woman walks up to him, and she puts her nipples inside his mouth, forcing him to milk her and swallow her milk. Works better with large breasts.

Keith was bound to a chair, and Sydney put him under forced milking. It pleasured her a lot.

Forced Milking by WhoDatFreshBoi March 25, 2017