My in-laws last year asked if I could babysit their 11-year-old this April so they could go away for a weekend, which they never get to do. I agreed and told them I would just need a few weeks’ notice to organize my own child care around it. Well, it’s April, and they still haven’t picked a date. I haven’t been able to make any plans of my own for weeks, and as we get closer to summer, the heat affects my health condition and puts me at a higher risk for seizures. My in-laws definitely need the time on their own and don’t have other child care options (my niece-in-law is poorly behaved), so I would feel like a bit of a jerk withdrawing my offer. But I feel like they’re not being very reasonable. Is it fair for them to keep me on the hook, or should I tell them I’ll no longer be available?