When you walk into the bathroom right after someone who made a ..... well let's just say a "stinky" and you get blamed for his/her mistake by the next person entering into the bathroom.
Johnny first experienced "poomiliation" at the age of 16 upon entering into the restroom at a fancy restaurant after the man before him had enjoyed his baked beans a little too much. The man in line behind Johnny handed him a bottle of Bean-O and told him to be on his way.
Phoom Phoom is what you'll hear when your head is sandwiched between two large breasts as said breasts are shaken back and forth thus smacking your ears.
Joe: that big tittiedho at the bar gave good Phoom Phoom last night.