Bondage

In the context of BDSM, bondage involves people being tied up or otherwise restrained for pleasure. Bondage is usually, but not always, a sexual practice.

The use of bondage between couples behind closed doors tends to be different from that associated with bondage in a BDSM dungeon. While "bedroom" bondage games often constitute foreplay, in the BDSM community, bondage may be an end in itself with no sexual contact at all and is often combined with infliction of pain.

Bondage themes have been present in pornography for some time. Bondage pornography for heterosexual men almost overwhelmingly depicts bound women, rather than bound men, despite one of the most common fantasies in both sexes being one of being bound.

source wikipedia