Pregnancy and the Public Library

The following interaction took place in the last 5 minutes:

I walk inside the public library and up the stairs, huffing and puffing a little but not too bad, proud of myself for coming here to try to be productive on this cloudy, otherwise depressing day. Overly friendly, nice, somewhat homeless-looking man grunts and says, "Excuse me, Miss, can I ask you a question?" I say, "Sure," and smile, because he is smiling, and I am friendly, and we are indoors with lots of other people around so I figure I can entertain a little downtown crazy for a few minutes without anything creepy happening. After all, randoms have provided all kinds of fun in my life.
He proceeds to nudge the disgruntled, angry-looking, missing-her-two-front-teeth woman next to him and whispers to her, "Ask her how far along she is!"
Grumpy lady shakes her head in refusal.
"ASK HER! ASK HER!" he loudly whispers, pointing at my belly. People are starting to look. I laugh and rub my belly and say something like "About 6 more weeks, give or take. Just about there!"
He gasps dramatically and shouts (yes, in the library) "OH, BUT YOU'RE SO SMALL! LOOK! Wow! Look! YOU'RE NOT EVEN LARGE! You must not have dropped yet."

What does that even mean?

I laugh politely and say, "Well, words like 'so small' are always welcome. You've clearly learned how to talk to pregnant women." Disgruntled woman: "He sure as hell better learn, bc I'm pregnant too. I have about 32 more weeks to go."

Awkward pause. I offer some polite congratulations while she glares at him, and then I begin to walk away.

Scary fellow to me: "Can I ask you one more favor?"
Me, laughing: "No, I will not name my child after you. I don't even know you."
Scary fellow: "No, no, no, I just want a profile shot. Will you turn to the side for me?"

Hrmm. This is awkward. What would you do in this situation?