Yesterday I was in a big Tesco store, sitting on a bench near the checkouts while my friend did her shopping. I noticed a couple in their 70s with a two year old, who I assumed to be their grandchild. The child was sitting quietly in the child seat in the trolley while the two grandparents paid for and packed a bag of shopping at the checkout.
The grandmother then came across, threw herself dramatically on the bench beside me and loudly exclaimed how exhausted she was. I made some polite reply.
She then announced
“ This is our first AND ONLY grandchild and he’s a real handful. Our son has a day off every Friday and we have to come and help him as he can’t POSSIBLY look after him by himself “.
I said I was sorry to hear that and asked if her son was ill or disabled.
“ No” she replied “ But GS is SO DIFFICULT , our son can’t get anything done with him there so we have him for the day. Our son’s wife is a special care doctor “ .
She said “ special care doctor “ in the tone of voice one might say “ international drug cartel boss “ or “ convicted murderer”.
I was a bit confused now and muttered something about that being a good job / worthwhile / they must be very proud etc.
She rolled her eyes and spat out “ Oh she’s a right piece of work her. She has no business being so selfish, neglecting our son and and leaving him in this position . He works very hard four days a week and he’s entitled to his weekends off “. 
Thankfully my friend arrived at that point and I was able to excuse myself and escape.