When a couple is about to perform anal sex and the man covers his dick in glue and proceeds to ram it into the girl's asshole, thus forming an inseparable siamese twin.
by BiigFrahh July 3, 2014
Bob1: Hey Bob2, why is there a girl standing right in front of you?
Bob2: Oh, we have a siamese dick.
Bob2: Oh, we have a siamese dick.
by MerpyMoo August 31, 2016
When your dick and balls are stuck together so bad from sweat, grime, and fromunda, that they won’t easily separate in order to pee, resulting in a poor stream.
My siamese dick is back today. It’s 90 degrees out and when I went to piss I needed two hands to free it from my sack.
by Goosey Goose July 22, 2020