Yeah, that "is he getting tired" "will he give up before I get there"-- YUCK!
One thing to keep in mind, Mojo, is that when you and your H did get it on, you were VERY compatible. In my moderately extensive experience (between the ages of 25 and 55) that is difficult to find. I only had one lover that I felt was truly and automatically on my wavelength. And he wasn't someone I wanted to or ever could live with.