Masturbating. Saying "Yoo-hoo!" to one's hoo-hoo. Ya-Ya-ing the sisterhood. Marching the penguin. Finding Nemo. Patting the bunny. Having fun with Dick or Jane. Choking the chicken or taking one's sausage hostage.
"Bored and waiting for my boyfriend to get back into town, I decided to play some solitaire."
"Old ladies love to play solitaire."
"Not now, honey, I'm playing solitaire."
"Playing solitaire is an awesome euphemism for masturbating."