Yes.. I have done it.  Especially if the kids are older.. and you are just dropping them at the curbside.. then watch them walk to the house and go inside.  You could evenwait for BM to come to the door (from the car).. and high tail it if she tries to come to talk..lol.

It falls into the favor category.. imho.. so if BM makes it a disaster.. then it's not a favor I would repeat.

I have done this before. I used to do it more often at the start (SDs were 7 and 9 when I met DH) and continued off and on until it became an EXPECTATION of me to do it, or for me to know, magically, when to be available even though no one told me a schdule had changed. Basically I started saying NO to doing so if 1) it wasn't an emergency and DH could do it 2) It was an assumption I'd do it and no one asked 3) If I had no say in the scheduling of it and 4) if SDs were not appreciative and thanked me for the help. Basically I haven't done a pick up / drop off in years (ok, maybe once or twice due to DH really not being able to do so).

I used to...until over time "things happened" and I am on full disengagement unless absolutely it works for me and is not out of my way even an inch.

I used to do it back when ss was 11/12 when school was out because our time started when dh was working. We had 50/50 split. I never had to interact with bm though. I just pulled up front and ss would come out and get in the car. I'd let dh know when I was almost there and he would call and tell ss to be ready. Most of the time ss was home alone anyway which is why dh didn't want to wait until after work. I wouldn't have done it if it required me interacting with bm nor would dh have wanted me to deal with her even briefly. Then again if she wasn't always leaving ss alone dh wouldn't have felt it necessary to pick ss up early... stupid step life drama

If you are taking the time to post here.  You don't want to do it.  It's DH child . He can't be to busy for his own kid. He should not be trying to give you a job he doesn't  want to do.  Either he picks them up or they can stay with BM. 

However, I did tons of it for school, Doc appointments, sports practices, day care, etc..... I registered him, etc....

I never had any formal standing. But no one ever prevented me from engaging medical care, or anything else.  I never needed any formal standing because I am and always have been SS's dad. At least since he was 2yo.  My actions were dad actions.

I did school pick up / drop off's for a few years. Only a few times did I go to BM's alone. B!%$^ be crazy. 

I did it twice daily for SS19 for over a year, to and from BM's mother's house on BM's weeks (SS was sleeping at BM's mom's house those weeks, but after school he went to SO's until about 9.) I did it because SO seemed to be really struggling and BM didn't seem to want to be bothered with it. In fact, the first time I went to SO's house at night to pick up SS19 (14 at the time), BM was also there to pick up the younger one. I thought to myself "If she's here, wtf am I doing here?" I tried to introduce myself and talk to her but she just stared at me and wouldn't speak. The other few times I tried to talk to her she pretended not to speak English (she has lived and worked in the US for 25 years and is married to an American.) Sometimes i wonder if by doing that, i contributed to her escalating bad behavior over the next few years. Who knows? I did what i thought was helping at the time. As stepmoms, helping is often rewarded that way from what i've read here.