How to politely shut down questions about being single?

I say "politely" because the worst interrogations about my singleness have been in group settings where I don't want anyone to see that they've gotten under my skin. I know how to stop the line of questions (projections) from someone when I'm one-on-one, but I struggle to maintain composure when I feel like I'm being humiliated in front of others, whether it's intentional or not.

Do you have any go-to lines you use? How do you handle? TIA