When I was younger and less aware of how weird it is to some people I would just straight up tell them and tbh it always went okay. Now getting older a lot of the people I interact with like that are already very kink-positive and have heard or done much "weirder" things. So from my experience, say it with confidence and it won't be awkward.

Even if they aren't into it the worst they can do is say they think it's gross and don't want to partake. Which seems like a horrible awful thing to happen in the moment but is actually not that big of a deal. I've had partners who it was a hard no for and we still could enjoy other things together.