Today, my DH took my car to work so I could take his in to get a leaky tire fixed.
Doesn't sound like a big deal, right? Well, I actually have ADD and keeping a routine is one way I find peace. Doing something out of the ordinary stresses me out. My DH didn't ask me to do it, and he was fine with waiting until Saturday so he could take care of it himself. However, I knew it was something that needed to be done and since DD is at summer camp all morning, I knew I'd have the time to do it, so I offered.
He was appreciative anyway, but because he knows things like this are uncomfortable for me, he was extra appreciative. And I love the guy, so it was worth it to me :)
Anyway, it may not be something exactly like this situation, but have you ever stepped out of your comfort zone to do something for your SO? How did he react?