If she still insists that it’s fine, then you can either choose to take her at her word or mention that her husband has brought it up. We don’t know the real truth here: whether it bothers them both more than they’re letting on, whether it bothers just him or whether his sense of humor is a little skewed and he hasn’t thought about it since. Regardless, at least you’ll know that you tried your best.
Best case scenario, you squeeze in an inquisition while you’re loading the dishwasher – and what’s the point? He might be rushed or defensive, and if there are problems with his partner he won’t want to discuss them then anyway. Give it another visit. Be warm and let him know that you love seeing him. And then call again. Not enough to make him block your number, but enough to let him know that you’re thinking of him. Frame your inquiries as an observation – he hasn’t seemed like himself – and that you want to be available to him in whatever way he needs.