A nasal squirrel is when a male is getting a blowjob from his partener while he/she is upside down. At the climax of the blowjob (during the ejaculation) the male attempts to seperate his balls and place them in his parteners nose, one in each nostril. This gives a tingling sensation to the testicals.
The "flying squirrel" is: grabbing ones testicle bag with the tips of ones fingers (both hands), and stretching the skin into the opposite dirrections. This should resemble a flying squirrel. Your "flying squirrel" is best displayed for people when tightly pressed against a glass window or door typically found in computer labs or a lobby of a public building where there is lots of glass pannels.
The act of a woman holding cum in her cheeks making them appear puffy like a squirrel's directly after performing an ass-to-mouth. The final step of the brown squirrel is to smack both cheeks simultaneously causing the cum to be sprayed violently from the mouth.