It may just be my personality but I have a very hard time understanding those who can't say no in their stepparenting situation....especially when what they are being asked really bothers them.
I say yes quite often, but I also use an equal amount of "no's". If something is a huge inconvenience or is a disaster to deal with for bm and my dh, why on earth should I be responsibile for handling it? Better yet, why would I want to?
I don't mind helping if I can. I can be flexible within reason. I refuse, however, to ever put myself in the position that either bm or my dh depend on me to get the dirty work done for them on a regular basis without my input. That is not what I signed up for. Thankfully, my dh respects me enough not to assume I will agree to anything prior to him asking me. Being honest, he did learn this the hard way when he and bm made plans regarding changing visitation that included me doing all the transportation. He failed to include me in that discussion. Sorry, this girl don't play that way. If I'm going to be expected to do something I'm going to be included in the decision making process or it's not happening.
I honestly believe if more would just step back, say no when they need to, and let the bios do their job (aka figure their own shit out) they would not feel like a doormat in their blended family life.