There’s nothing wrong with what you’re saying here as far as your own perspective goes. But what you’re ignoring is that a middle aged man should not be comfortable with a 20 year old as a partner. When you’re standing on the 45 year old side of it, 20 looks and feels extremely young and inappropriate. Which means you’re dating someone who is totally comfortable with inappropriate situations. Want more proof? Look at what he’s doing with his ex.