I like JaneQ's suggestions here. I think there is rich potential for humor, and for using humor to expose more people to the idea of poly relationships.
However, I think you would have to take a few minutes to explain what poly is, because most people simply haven't heard of it or would assume you're talking about threesomes or swinging.
I think it will be very challenging to tell jokes about poly situations because the audience might not believe you're serious that poly relationships exist.
Personally, I find that when I tell people about my relationships/dating life, they think I'm joking. They outright laugh and cannot believe I am serious. So...actual humor would be totally lost on the audiences in my life.
But best of luck; I think it's a good idea to try. I really admire gay comics who have helped to "normalize" gay relationships through humor. Ultimately, humor unites people--we realize we have things in common because we are all experiencing the same things, all laughing at the same things.
And if you ever end up with two or three mothers-in-law...well, there's a whole stand-up routine right there!
Single, straight, female, solo, non-monogamous.