I am tired or repeating myself over and over again to my parents with dementia.

Have you told your dad that you DON'T need him to make things any harder on you than they already are???
That you are NOT here for his amusement??
He is obviously trying to "get a rise out of you".
A little behavior modification is in order for him. Try ignoring him or walking away when he acts like that. Do something you know irritates him. Don't make a contest out of it, but if you give him negative reinforcement he may get the hint and start showing a little more compassion.
NO need for the guilt. Your mom has dementia which cannot be changed easily, but your father on the other hand shouldn't be abusing the one doing all the work!!!

BMO:

Do you know why they keep pushing your buttons? ... Because they installed them!

Instead of responding properly, you're reacting to everything they say and do to upset you. Example: since Dad is the instigator, cut down his privileges as good parents do with their impish or brattish children. He's probably bored, so find something for him to do instead of laying around like a lounge lizard. If Mom wants to spin and spin like a top, let her. Or find something for her to do to channel all those random bursts of energy.

As a last resort, make them an offer they can't refuse: either stop the nonsense or move out. People will disrespect you only when you allow it, so make sure whatever rules you set are enforced consistently and lead by example.

Keep us posted.

-- ED

It sounds like your father doesn't know how to 'deal' with someone with Alzheimer's.

For starter's I would recommend that you get a copy of Coach Boyles Playbook for Alzheimer's for Dad.

Ed was right on with his answer as Dr. Phil says we teach people how to treat us. Your Dad has to stop making things harder for you and since he can understand what is going on he needs a good talking to if he wants you to continue doing all that you are doing he needs to be part of the solution and needs to step up and help you maybe he can take her outside for walks each day to give you a little break.

Again, please allow me to be the voice of reason here, and if the FATHER doesn't know what is 'happening to his wife' he isn't going to know how to communicate with her, and he is probably unableto communicate that to you.

Why not join a support group for caregivers and BOTH Of you attend? The book I listed above should help before going to a caregiver support meeting, but your father will not agree to going to a meeting, then perhaps there is a friend HIS age that YOU can talk to and explain the situation and ask for their help.

It takes a great deal of skill to maneuver the land mines of Alheimer's and without the proper knowledge you are BOUND to step on quite a few land mines.

If you can get your mother to attend a DAYCARE center to help give all of you a break. Perhaps while she is at the center you can have a calm converations with your father. Here is another article on how to deal with Alzheimer's:

http://www.alzheimer.guelph.org/downloads/12%20pt%20Understanding%20the%20Dementia%20Experience.pdf

You have to copy the entire link above (not sure if it will be a 'hotlink or not) but it worth the read.

Thank you everyone for your help! My Dad has been a very mean man all his life and I really don't expect him to change now. I have tried reasoning with him and at one point told him he had to go. He is also unable to care for himself due to a stroke, so the idea of going to a nursing home made him a little nicer for a short period of time. I have 2 sisters who do not help with the care of our parents and sometimes they are very judgemental of me. Their answer is to ignore him because he is a "poor old sick man." I guess I'm still the "little girl" trying to get some sort of approval from her Dad.

We all want good, loving relationships with our parents, but if it hasn't happened yet.......You can wear yourself out & down reaching for that brass ring but never get it.
I care for my mother but don't expect her to care for me. That's just the way it is & I've come to accept that.
The best thing you can do for yourself is to let it go. No point in having your heart broken daily. You're sowing seed on stoney ground.