Parent advice: My married a woman a year older than me. Their expectations for me are too much.

This is a newsletter bonus question. Care and Feeding is Slate’s parenting advice column. Have a question for Care and Feeding? Submit it here .

Dear Care and Feeding,

My parents divorced when I was 15. I am now 25, and my dad married a woman who is a year older than I am. I wasn’t thrilled that my dad married someone young enough to be his daughter, but that’s not the issue I have right now.

Now, my dad and “Britney” now have a son who is a little under a year old. He and Britney are forever after me to take him for the afternoon or even most of the day, supposedly so we can form a sibling bond. I suspect they are trying to use me as free child care and have steadfastly refused, which has angered them to no end. As far as I’m concerned, if they didn’t want to put in the effor