I have this question about jerkin the bird?

Yo, so I went to jerk the worm, nah, just kidding, the huge andaconda six foot shlong...getting sidetracked. Anyways, I went to jerk, then when I was reaching full peak, some weird stuff happened. A tensing around the inner part of the dong, that didn't feel as awesome as usual, felt really weird. then it just oozed, rather than shooting in a kleenex. What gives?