Funnel gag
From Wipipedia
A funnel gag consists of a funnel with a tube leading from its spout into the mouth, usually with straps to hold the tube in. Such a gag is used to force the bound person to drink something (often the dominant's urine).
Warning: It is very easy to choke during such forced drinking. For issues regarding the consumption of urine, read the article on watersports.
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