Most Helpful Guy
that's a pretty significant age gap. Lots of room for issues, i think you'll look back and be a little creeped out that a 40 year old had any interest in a 20 year old. sex is probably one of his big motivations.
Most Helpful Girl
it might be hard on you since you like him, but yes it's kind of weird if you look deeply into the future, imagine yourself married with him 20 years later, you will be 40 years, meanwhile he will be too old even for your children, after all the gap between is actually huge.