Bedtime

So I am scared of bedtime. I didn't realize this before, but I haven't put Ethan to bed in quite a while. John does it. We (he) started a new bedtime routine a few weeks ago and I've never done it. Oh, I know the routine, but I don't know if Ethan will be OK with me doing it. I love that John gets to spend that time with Ethan each day (and I know they both love it too), but maybe I need to jump in every once in a while so that it's not such a big deal when John can't be here. If you hadn't already figured it out, John won't be home tonight to put Ethan down. He is going to a seminar for work, so Ethan's bedtime routine falls to me. I take care of the boy all day, and put him down for naps multiple times each day, so why does this scare me?