My most memorable one was also with the woman with whom I lost my virginity. She was the first woman to see me 'full size.'

We had been heavy into foreplay and groping and when I lay back so she could use her hands and mouth on me, she just had this 'look' on her face as she stared at my dick, stroking it, and looked me in the eyes.
I said "What?"
She said "You're huge!"

Made my day.