Trevor has been making more of an effort to support me with the horses. When I have to exercise Snickers (but not necessarily ride him, so Trevor can stay with me or nearby the whole time), he's been offering to come out. He mostly watches, and then helps me with Snickers' buckets, but also asks a lot of questions and interacts with me about the horses. I asked him (semi jokingly) if he wanted to lead on time, and he said he's not quite there - yet. He's trying to get more comfortable so that he can actually interact and help me with the horses.
The best news is that Trevor made me an offer! He said he thinks he'll be ready to learn to ride as soon as Flash is ready. Which means he bought himself another year, considering Flash is not even green broke yet, much less big enough to carry Trevor. However, it's an effort and a commitment. It also gives me the extra encouragement to really make Flash the most excellent horse possible for my hubby :) It's so exciting!