Sorry to hear this is the way tings are going - second the power of attorney recommendation - best long term plan I think is to spend down their assets and get them both into Medicaid, then into an assisted living or nursing home - good luck...
Dementia peels off the veneer of civility"
...so true. Dis-inhibited behavior is one of the more difficult challenges with beloved parents in a public sphere. It's one thing to address social improprieties in private, and a whole 'nother (all-too-often-deeply-humiliating)issue to deal with an uninvited/unintended audience.
Whether it's untimely potty-mouth, not-so-subtle-rude-impatience, uninvited incontinence, flatulence delivered in public with Olympic flair, foul-mouthed temper tantrums, or something as tasteless as watching your loved one repeatedly flip/flop a loose denture in and out of their food filled mouth while at the dinner table in a nice restaurant. None of this is intentional and you should not take any of it personally - despite how personal the effort to clean up the momentary disaster becomes.
A very important comment above reminds those of us in the "sandwich generation" (responsible for children, grandchildren & parents & sometimes even grandparents):
"You can't control their behavior but you have total control over how you let it affect yours."
- may sound 'selfish' and invite unwarranted pangs of guilt...Is unquestionably, very sound advice.
The Serenity prayer reminds me each day to put things into perspective:
GOD, grant me the SERENITY to accept the things I cannot change the COURAGE to change those things which I can & the WISDOM to recognize the difference Freepers are full of sage advice and I/we pray for you and yours - Godspeed on this challenging journey.