A man is receiving oral sex from his partner. The partner proceeds to stick his or her thumb in his butthole to increase the pleasure level for the man, when the man promptly farts on the partner's thumb. The sound makes a reverberating PRRTTTTHHHT like an amateur on the trumpet. Often accompanied by a rotten egg odor.
"Everytime he tries to tickle my anus I let out a Fuzzy Trumpet"