Wives & girlfriends, when do you sneak in your me-time?

I know my wife masturbates occasionally, which I encourage, but she isn't open about when and how. she knows I do too, but we don't share those details.

When do you sneak it in and how? Over your clothes in the car? Sneak in a rub and a finger in the shower? Naked and sprawled out on the bed when the house is empty?