Twixing

An act that is undertaken by two people. When one person sits on the lap of a person who is already seated upon a toilet.
When in position, both parties defecate. The person who is seated "on top" defecates between the legs of the already defecating person.

Thus giving the appearance of a Twix hanging into the toilet basin.

Howay, let me in the bog I am desperate for a shite. I don't mind twixing with ya.

Twanking

The act of masturbating tramps

I have been out all night Twanking, now my sleeve looks I've been mixing PVA glue.

Fanny Dodger

A male who does not like to have sexual relations with females

How that Dave is a reet fanny dodger isn't he.