This is a Montreal (which has a great public-transport system) term, that I first
heard in the late 1950'
s. A tweezot is a
pervert who gets down on his knees to suck the farts out of the cushions of the back bench seat of a bus, particularly if an attractive person has just relinquished that seat. The back seat was favoured because on the older Montral busses the row of seats in
front of it had a sort of panel that blocked the driver's view of anyone crouching down there. (The busses have since been redesigned.)
A young secretarial type stood up to get off the crowded bus at the
next stop. I tried to
push my way to the vacant seat, but some tweezot got there first.