My PIL divorced some years ago. Last summer, we had them both visit, in quick succession.
MIL's visit was lovely, but stressful and distressing, because she was in her last months of life, due to cancer, and was a shadow of her former self - she was an amazing mum, MIL and grandmother, and it was so hard seeing her unable to eat much or walk any distance at all. But we had the best time we could with her, and made some good memories.
Less than a week after she'd gone home, my FIL came for a visit. Almost the first thing he said when he got into the house was 'It's wonderful, you know, how well I have kept my health - I am never ill!' Considering that he knew how poorly my MIL was, dh and I were pretty gobsmacked at this utter tactlessness. I didn't expect him to be as emotional about it as dh and dbil were - they were divorced, after all - but I DID expect him to have a little care and thought for his son, who was about to lose his much loved mother!
In the end, I took him aside, and told him, quite bluntly, how tactless he had been. He didn't apologise.
When MIL did pass away, it did not occur to him that his sons might be in need of some support from their father - the odd phone call, perhaps, to see how they were coping - none of that. I even told him directly, on the phone, that they could do with a bit of parental concern from him, but still nothing.
His main concern seemed to be whether he could have the kitchen cutlery and implements, and the fact that he would no longer be classed as the Chief Mourner. He has all the tact and sensitivity of a house brick.
Actually, that is not fair. I like house bricks.
On a lighter note, when he came to stay, he was with us for 9 days. For those 9 days, his entire wardrobe consisted of the following:
2 pairs cotton chinos - beige.
2 heavy cotton shirts - beige.
1 heavy cotton jacket - beige.
1 waistcoat - light brown.
1 tie - dark brown.
Every fucking day, he wore beige from head to foot. We had considered a trip to the beach, with the dogs, but didn't dare, because we'd have lost him as soon as he stepped onto the sand!
And because he is deaf, he can't join in the conversations, so he monologues instead. Supermarkets Of Penzance, was one monologue that I heard pretty much every day he was with us. Bell Ringing And Bell Towers was another one. At one point, he and I were left in the car, whilst dh and FIL's lady friend nipped into Sainsburys. Because we were at a fucking supermarket, I got the Extended Play version of the Supermarkets Of Penzance monologue - I was texting dh throughout telling him I was going to kill someone if he didn't come back to the car soon!
We are coming up to the time of year when he will be wanting to plan a visit to us. I have already made it abundantly clear to dh that a) the visit should be no more than 5 days, and he is to make sure of this, and b) he (dh) must be on annual leave the whole time - if he thinks he can book the odd day off, but leave me to entertain FIL the rest of the time, he is sorely mistaken - I have said I will leave home!