One story that combined both:
I was carefully decanting liquid from one vessel into another in the Navy Yard, and in so doing, my abdomen protruded rather more than usual. A young, very thin woman in the lab lifted a long piece of glass tubing, and said, "I think I'll let the air out of your belly so that you'll look more like a man."
"Good idea," I said, still decanting. "Then you can take the air and use it to puff up your chest so that you'll look more like a woman."
Asimov liked to flirt with pretty girls. For example:
I once came to Boston University to take Robyn [Asimov's daughter] out to a steak house for dinner. She asked me if it would be all right to take her roommate. I said sure, and she brought along five roommates.
Every one of them was twenty-one years old, every one of them was beautiful, and I kissed every one of them.
One of the young ladies said, "Oh, Dr. Asimov, you behave just as Robyn said you would."
"What do you mean?" I said.
"Well, you kissed us all."
I said, "Don't the other daddies kiss you all, too?"
"No," they all chorused. "Robyn said you would be the only one."
His first wife reputedly looked just like Olivia de Havilland:
I couldn't find a picture of her, but it's probably true, because they produced a breathtaking daughter Robyn:
However, Asimov was deeply unhappy with his first wife. She criticized him frequently, and was reputedly frigid.
After twenty-odd years, he divorced her and remarried a sweet, tender woman named Janet:
Asimov writes, "Now, my dear wife, Janet, considers herself plain and, every once in a while, feels sad about that. To me, however, she is the most beautiful woman in the world, and my heart invariably leaps up when I see her unexpectedly, and she knows this."
I am very touched by this, considering his numerous discourses on his appreciation of cute girls. His love for Janet is clear through the small details, for he always refers to her as "my dear Janet", whereas his first wife is described as "Gertrude, who loved enumerating my faults" or "Gertrude, with whom I don't have many happy memories".