I think it would depend on who exactly is asking. My little christian friend, who probably thinks blowjobs are just the naughtiest thing out there, might get the suggestion of some very mild kinks, like a blindfold in the bedroom or getting one of those dice games where you have an action die and a body part die. My more ‘experienced’ friends? I think I’d recommend some breath play, to breathe that fresh air in, or some light pain/stimulus/deprivation. Remote control toys that are controlled by the partner during the day are always good as well, especially if it’s not (because they’re new and we’re being safe about this) something that could get them in trouble.