My 4-year-old son is a wonderful big brother to his one-year-old sister. However, I feel bad that many times when he wants me to play with him, my answer is "OK, just as soon as I finish taking care of your sister."
Is there another way to word my answer so he doesn't begin to feel his sister gets a lot more attention, or that he is always "put on hold" for her?
Your little guy sounds like he's handling things just fine but I understand how you might feel you're brushing him off too much. First, take your cues from him, does he seem like he's sad, anxious, clamoring for your attention, moody ? My bet is you're giving him all the attention he deserves, and he seems like a boy who would enjoy doing"babycare" things with you. As far as another way to put your "just as soon as..." statement, how about saying things like "I can't wait to finish diapering your sister so we can play together!, While I'm finishing up with your sister let's both think of where we'll pretend to fly on a magic horse!" These can be said with an animation and positive expectancy in your voice. When you do begin playing with him always make reference to him being a patient boy and occasionally plan to do something special with him outside the house, just the two of you. It's so nice to communicate with such a compassionate parent. Enjoy your kids.