My sister and her husband recently bought a house and had a baby. I love my niece and enjoy looking after her. I have no children of my own. However, I find that I am getting asked to babysit when my sister is out but her husband is home. The reason is that he is working on the house so they can renovate and sell within a (self-imposed) set timeframe in order to make some money. In order for him to be able to do this, they ask me to look after the baby. So as not to dripfeed, her husband has form for both being a bit obsessed with money AND with being a bit useless with my niece. I'll happily admit that this really gets on my nerves. I see it as being exceedingly selfish and thoughtless. My view is that they decided to have this baby together so therefore it is partly his responsibility. He tends to stand back and let my sister or our mother (if she's around, doesn't live nearby) look after the baby.
Am I being unreasonable to decline to babysit in this particular circumstance? To be clear, I would happily babysit if he was taking my sister out for a date night or if they were doing something together.
PS. First go at AIBU. Please be gentle :)