If mom has dementia and sees herself as a much younger woman, she may indeed have a crush on your hubby. Gently remind her that "he" is taken and that she is "taken too" by Dad.
Have you noticed any special attention your mom pays toward your hubby? Is dad off base? I'm not saying anything untoward is going with a possible crush your mother may have on your husband. Have you asked hubby if he's noticed any extra attention from your mom?
People with dementia go through all sorts of phases and they seem to get stuck in a loop. The loop runs and runs and runs until a new and different loop begins. All you can really do is try and redirect dad's attention whether mom actually has a crush or not.
Do research on your father's dementia because new things will constantly pop up. Good luck to you and your entire family.
From various readings this seems to happen sometimes. It can be a person in the household that becomes the focus of this, a care provider or even a fictitious or former beau. Dementia really messes with reality in the person's mind. Accusations abound, including theft, abuse, lack of care, etc.
This site is more geared for how the spouse can handle the situation, but the information helps in explaining why it happens: https://www.verywellhealth.com/partner-dementia-unfaithful-accusation-97645
You might discuss this with his doctor and see if there might be any medication to tone down his anxiety (sometimes this can be behind accusations.) Many do come with a fall risk warning, but a minimal dose shouldn't impact someone unless they are already a fall risk. My mother had to take some during severe sun-downing due to UTI. She never fell while on it. The few tumbles she had in MC were unrelated and not during the time she took this medication. She also wasn't "doped up" on it.
Since you both live there, it will be difficult to get his mind off this delusion. If/when he gets into this "rut", the best you can do is try to redirect his focus onto something else.
What is your mother's take on this? Does she understand he's thinking this and does she attempt to reassure him or is it out of her capability? If possible, limit any exposure of husband to dad. It will be hard since you all live together, but the less often dad sees him, perhaps the less often this "idea" will pop into his head.
It may be possible that Dad is correct, and Mother does indeed have a crush on your husband, her son-in-law. They may even both be suffering from dementia! Checking on Care Topics is very good advice. You could talk to Dad and ask him what he thinks is happening – whether mother is making advances to SIL, and whether SIL is responding to her inappropriately. Or is it just that Dad is missing something in the marriage, and resents mother complimenting SIL. You can also ask him if he thinks they should move out into AL. A conversation with him that doesn’t start with the assumption that it’s all Dad’s dementia, might help you to work out what to do.
Katwilk, I see by your profile that your Dad has Alzheimer's/Dementia, which could cause your Dad to think like that. As for how long this phase will last, it is hard to say. When that phase leaves, another will take its place.
You and your husband need to be ready for these different phases. Go to the blue/green bar at the top of the page and click on CARE TOPICS. Go to Alzheimers & Dementia sections and read all the topics you can to get you ready for the future.
People with dementia go through all sorts of phases and they seem to get stuck in a loop. The loop runs and runs and runs until a new and different loop begins. All you can really do is try and redirect dad's attention whether mom actually has a crush or not.
Do research on your father's dementia because new things will constantly pop up. Good luck to you and your entire family.
This site is more geared for how the spouse can handle the situation, but the information helps in explaining why it happens:
https://www.verywellhealth.com/partner-dementia-unfaithful-accusation-97645
You might discuss this with his doctor and see if there might be any medication to tone down his anxiety (sometimes this can be behind accusations.) Many do come with a fall risk warning, but a minimal dose shouldn't impact someone unless they are already a fall risk. My mother had to take some during severe sun-downing due to UTI. She never fell while on it. The few tumbles she had in MC were unrelated and not during the time she took this medication. She also wasn't "doped up" on it.
Since you both live there, it will be difficult to get his mind off this delusion. If/when he gets into this "rut", the best you can do is try to redirect his focus onto something else.
What is your mother's take on this? Does she understand he's thinking this and does she attempt to reassure him or is it out of her capability? If possible, limit any exposure of husband to dad. It will be hard since you all live together, but the less often dad sees him, perhaps the less often this "idea" will pop into his head.
You and your husband need to be ready for these different phases. Go to the blue/green bar at the top of the page and click on CARE TOPICS. Go to Alzheimers & Dementia sections and read all the topics you can to get you ready for the future.