A sexual act between a male and female in which the male enters his penis in both the female's vagina and anus in alternating fashion, much like the motion of a needle on a sewing machine.

when you've done something so cringe you can't stop replaying it in your head and it stops you from getting on with your every day life

(male variation) typically when one man uses the shaft of his penis to tickle the entire length of another man's penis by quickly tapping with the girth of penis #1 up and down the side of penis #2. This is called a sewing machine for the fast rhythmic pattern used by penis #1, also typicaly noted for making man with penis #2 hum with joy like a sewing machine.