The first thing I thought of is my neighbor lady who always stops during my heat of the summer rides and INSISTS I take a gatorade from her cooler.
Here in AZ most locals carry a cooler with them whenever they go out from April - Oct. I call it my "just in case cooler"... As in "just in case I get a flat tire when it's 116 out"...
Anyway, there is this one lady who stops whenever she see's me taking a break on the side of the road and insists I take a cool gatorade and some ice for my neck. She really is a cute lady and always tells me I'm nuts to be out riding in that weather.
But yeah, back to your guy... UGH! I would have been WAY creeped out! Those kind of things make the hair on my arms stand on end. YIPES!
You did the right thing tho, polite but firm. Keep moving and make sure you have that "I'm a nice lady but could rip your penis off in one swoop" look on your face. I learned that look when I lived in New york.