When a man removes condom during sex without his partners knowledge or consent.
Legally considered a form of rape or sexual assault in some places. Considered a shitty thing to do everywhere else.

when you're hungover as shit after a spending a night drunk as a skunk

Stealthing is when a man removes a condom during sex despite agreeing to wear one so that he can cum inside the other person without their knowledge.

To fuck "safe" intentionally with a faulty condom - therefore end result is a bare fuck with the receiver under the impression a condom is fully intact during intercourse to climax.

Removal of a condom during sexual/homosexual intercourse without mutual awareness.

Wearing a face mask into the store and then removing it when no one is looking, similar to removing a condom without ones partner’s knowledge