While one is relaxing in a hot tub with others, the act of poking the head of one's penis just above the surface of the water, like a submarine's parascope.
When a male proceeds to drop his tescticles onto anoter persons eye sockets (consciousness is not an issue) and then place his erect penis on their forehead therefore making it look like the person is looking through a parascope
n. a penis trick, while in a hot tub descretely remove your penis from your swimwear, then slowly raise your body until the tip of the penis has breached the surface to the surprise of the other hot tub residence.
The act of sitting on a girls face, with your balls resting on her eyes as if shes peering through the lens of a periscope, while she simultaneously jerks you off.
When you press your butt against a hard, flat-surfaced chair and fart, but there is no place for the gas to escape except up the crack of your ass. and out at the top.
Dude, I laid the biggest periscope fart in detention. I press my butt cheeks against the hard chair and farted and the gas came bubbling up the crack of my ass and peeked out at the top!