When a girl (or guy) jacks off a guy until he ejaculates into a toilet.
Person 1: Man last night was crazy!
Person 2: Why?
Person 1: Because my girlfriend was jacking me off, and I didn't have any tissue.
Person 2: So what did you do?
Person 1: I had her jerk me off into the toilet so there wasn't any mess.
Person 2: ...wtf.
Person 1: Toilet Jerk man!
The toilet jerk is when you jerk off on the toilet. Most likely to happen after being denied from a female or before taking a shower.
John: Yo this chick finessed me tonight after she said she was gonna come thru and suck some dick.
Adam: Damn man, rip a toilet jerk and call it a night.