I thought that might be the case.
I think another poster might be right though that it's not so much good sex, more when he is satisfied with your sex life.
What you've described sounds very quick, very formulaic and tbh pretty damn unsatisfying. I'm not dismissing the joy of a quickie occasionally, but it's like the kids go to bed, he jumps on you, always finished in the same position (baffling) and that's all by half past 8 in the evening (and then at 5am).
There's no luxuriating on it, taking your time, playfulness, joy. It sounds very perfunctory. I know kids mean that taking your time can be tricky, but there's still a balance to be struck. I'm not saying you need 2 hour sessions with a bunch of sex toys and swinging from the chandeliers, but there's something in between which most of us want. And it can't be squeezed into half time of a football match...
I'm not saying this to make you feel crap about the sex, but because he's fed you a bunch of lies about what 'normal' is, and you've never had a decent sexual relationship, so you might not know.