I can understand that - in bed, sick & under the covers trying to keep warm - and daydreaming. Doing it yourself in the middle of the workday, sick, for me it would be thinking of dirty things with my Mistress she would never, ever do. Then cleaning up, napping, waking up aroused and doing it all again. I've been there.
Favorites in the past few years involve my Mistress. After entertaining and worshipping Mistress, especially after she pleasures herself, I usually stand up with just a dog chain around my neck while Mistress talks dirty, flaunts herself, I do the deed. Then there is my Mistress' favorite, which means it is mine too. She orders me to put pee pads on the floor, orders me to masturbate, as I get close to cumming she strips off whatever she has on, squats and showers my groin and chest as I cum. The first time we did it that way I felt euphoric, emotional, and completely owned & connected to Her. She laughs and says she loves the expression on my face when that happens.
(Just writing this I need to take a cold, conventional shower immediately. LOL!)