Your sibling definitely sounds like he has an agenda. He is also not sparing a thought for your father's wellbeing, or indeed yours. It would be too unsettling for your father to go abroad on holiday or even on holiday within the UK, not only because of the nature of dementia, but with a son he only sees four times a year for short visits and who has no understanding of the care involved. Let alone what your brother is trying to achieve, which could be to get him to agree to something untoward. If your brother really wants to spend time with your Dad, he knows where you both are and can make a date to visit or, at a stretch, take your father out for the day/weekend. I would change the locks on the house if he thinks he can come in when you're out, by the way, and I would also 'lose' your Dad's passport too and get a letter from the Dr to confirm your Dad could not travel out of the country anyway. My sisters spent less than once a year visiting my Mum and left me to everything, yet 6 weeks after she went into a CH they emailed me jointly to say I needed to 'act in her best interests, rent the house out and manage her possessions'. It was too soon for me to comprehend the sadness of my Mum's situation, come to terms with all the stresses and depression it had left me with, let alone the sheer sense of entitlement that seemed to come out of the woodwork from them. I feel very strongly about this sort of thing. You look after yourself and your Dad and, if you can, speak to your sibling asap to explain a visit would be best to start - you are doing one of the most difficult jobs in the world with integrity and care - and your sibling should be the one hiding under his duvet in shame! They don't seem to have a conscience though these siblings do they.......................just pound signs before their eyes.