It's taken me 10 years to realise this.
But he is dead-pan and he never ever smiles. When we talk about anything he has a very vacant expression or frown on his face. He does laugh but rarely and only really at what I would describe as man humour.
I've been unhappy for years and it dawned on me yesterday that rhe lack of smiling has actually really worn away my love for him.
He used to laugh more because we would spend our weekends with other couples and he'd laugh at the man jokes. It's only since DCs that I've realised how little he smiles. Living with such a joyless man is making me quite sad.