I saw someone post about this earlier but it got lost on my timeline, but the idea of having a free use code with your partner based on jewelry or clothes or something (ex: if I'm not wearing a ring, you don't have to ask) sounds incredibly hot. Gonna talk about that with them tonight...
Update: pitched the idea, got used like a toy, going to sleep now. 
@msd i wanna do this with a skirt-length code. As much as i fucking hate the phrase, having an "asking for it" length between me and my partners is mindsizzlingly hot to me.