daintpiss

A daintpiss is a person that loves to make plans but loves even more to back out last minute, turn up later and then continue to be an absolute wanker. Not someone youd introduce to your parents or other mates as it would be social suicide. Daintpiss' usually come from people with the last name Dainton.

Jack: "Sam is always late, and he always pisses me off"
Seb: "Just like Harry Dainton!!"
Tom: "What a daintpiss"