An accidental dick-grab when one is unbalanced or falling over and reaches for something to grab onto for support. This usually lasts for a short period of time, followed by a considerable amount of awkwardness, so it is considered a 'tease' rather than a full squeeze job. Bonus points getting the whole hand around the girth of the penis.
When I was at the ice skating rink last week, I gave my friend an over the pants squeeze tease, after which I bruised my tailbone on the ice.