expanding on the idea that you two are not together, your Dom entering the store first and then you, you can do tasks at the supermarket...buying a big cucumber, condoms and personal lubricant like ky, and nothing else, while you have a bullet inside you whirring away
There is also buying things with slut money, money that has nasty things written on it, like "I am a dirty sex toy" or "I like being slutty" in bright letters as you hand the money to the clerk the words showing
of course both of these you are dressed rather provokatively...no panties, bra...well you get the idea