This is where I come from. My dad was 20 years older than my mom. They loved each other and had a very stable marriage for 45 years until his death a few years ago. Their relationship was like a rare jewel.
He was 39 when he married my mom at 19. He was always a wonderful dad and husband. I do believe there is a double standard where this type of relationship is concerned because while men can be much older than their female partners...women come off looking as if they are desperate or something. Maybe it's not fair but that is the way it seems.
My dad live to the age of 83...so mom was 63 when he passed. He was disabled the last 15 years of his life. While mom took great care of him and did it willingly it was still a strain at times. She did have a great social life...church activities and such but I'm sure she would have loved to have been able to do things with Dad on her arm.
Now, I'm not one for fling type relationships so if you are going to date this guy for a thrill then none of what I said really matters...does it? But if you are looking for long term love then there are many things you really should contemplste before you or he becomes attached to one another.