The interjection PFFT (pronounced "pufft") is used to dismiss something that someone has said or typed. When used as a direct response to a statement by another person, PFFT can often be considered quite rude.

Pfft is a method of expressing lack of interest, disbelief, or disapproval of someone or something in chat.

You'd never forgive yourself — and then you'd never forgive me, and then pfft, the end of a fine friendship. Used to signify sarcasm or disagreement.