Taking a "pet" out for my morning walk
I've always wanted a sub who was so willing to be under my complete control that she'd essentially become my little free-use toy in and outside the home.
She'd have a leash attached to her collar whenever we step out and walk alongside me in the outfit I picked out for her that day. When we arrive at my local cafe, I'd tie her up out front, leaving some part of her exposed by undoing a few buttons or pulling her panties down around her ankles; whatever I was in the mood for everyone to see that day.
When I emerge with my drink, we'd find a spot to sit down so that she could kneel on the little pad she carries around (her sole possession) and take me into her mouth while I enjoyed my coffee in a spill-proof thermos.
Folks passing by would look on in desire, envy, or disgust, but she wouldn't be allowed to stop to acknowledge any of them without my express permission. I like the idea of someone asking if they can "pet" her by twisting a nipple through a thin top or running their fingers between her legs.
If we had a particularly curious onlooker or two, I might even let them determine where on (or inside) her body they want me to cum. Either way, she'd wear that slow, sticky drip like a badge of honor during the return walk home.