I've seen it from both sides. When I first started work there was stunning movie star type mid 20's woman going out with a mid 50's manager. I was jealous but I did realize that I would feel very uncomfortable being with her in real life. I was just starting out and she just seemed out of my league. The manager was a great guy and very confident - it actually seemed a natural fit.
Zoom ahead and I have had a few girlfriends younger than myself. I found the comments came from the women more than the men. I remember a middle aged sales woman who was very friendly towards me until my girlfriend joined me at checkout. 'So it's like that, is it ?' and her demeanor turned ice cold.
If I may suggest a few responses for 'Where did you meet ?'
1. I use to babysit her.
2. We met at a penis reduction clinic that she worked at.
3. I won her from her father in a poker game.
4. I am a hypnotist and she is a subject.
5. She was born February 29 and only ages one year to our four. She is actually 102.
Here is a couple more that would help people remembering to mind their own business: "She was my lawyer who got me off very serious charges" or "We met at millionaire dating dot com".