@CleopatraTomato
I lied with great abandon to all my patients. Every single one.
I looked after a lady whose dog had died seven years previously. I can remember her asking me where the dog was - so I said he was at the vet's overnight.
Cue anxious old lady asking what was wrong. So I said it was for a diabetes check. (The dog had had diabetes so the lady was fine with this.)
Cue anxious old lady asking when the dog was coming home. So I phoned DH and told him he was (temporarily) the vet. Handed the phone to the lady and DH told her the dog would be coming home the next day.
The lady was satisfied with this and the conversation moved on to where the sherry bottle was (another topic which was done to death.)
My point is that you need to buy in to people's delusions to keep them happy.
I absolutely take your point though - there is a line which has to be crossed. People with dementia are not all at the stage where they will be satisfied with kind lies and it is hard to know what to do for the best.
Generally though - I would say that lying to keep them happy is definitely the best thing to do.
DH also "became" a farmer who had a cockerel which the lady wanted at some point. He got used to being whoever the lady needed to keep her happy.
And DD once had to pretend to be a lady's son's secretary. The lady wondered why her son hadn't been to see her that day. (He had but she had forgotten.) So I told her that he had been delayed on business elsewhere and had to stay the night. DD pretended to be his secretary and made up a story in which he was staying at a hotel overnight on business.
When I think back on all these lies do I feel guilty? No. I would be feeling guilty if I had spent hours telling patients that their dogs were dead, that their sons had visited. It is cruel to do this. It is kind to tell downright lies.