So I walked up to him instead. I was curious how he did with crossing water, and the irrigation pond was over full, leaving a nice shallow area to try out. I was in tennis shoes, so I tried lunging him into the water, but he was too smart for that. Nathan didn't mind getting wet, though, so with some instruction to watch Trigger and not be directly in front of him in case he blitzed through or jumped, they were off. Nathan, of course, walked directly in front of Trigger, but he walked gamely across, no biggie.
I took Trigger back from Nathan for the walk back through the "scary" sprinklers (there is only one gate, and it was on the other side of the sprinklers), because I wasn't sure what he'd do. I tried to time it, but we were going against the rotation of the sprinkler, so we got hit. Trigger tossed his head at the same time I did (I got hit in the ear--not sure whether his was his ear, eye, or just head in general), but other than that, we both trotted through with no issues.
He is a dream to lead--slack lead rope, goes wherever I tell him. Only issue is that he likes to "hug" me sometimes, and needs an elbow to remind him to skooch back over. I walked him on the asphalt air strip (yes, it really is, but not very active, and it's also the "road" we drive on to get to the barn, and is a shorter route between the gate of the pasture and the gate of the arena, and that's where we were headed), and he did just fine. I walked him across some poles on the ground outside the arena while Nathan was opening the gate, and Trigger was like, "I'm not sure WHY, but whatever." We got the giant horse ball out again, and this time he wasn't nearly as scared of it, but he also wasn't all that interested in it.
Having spent a few hours on pasture, he wasn't very hyper, so after he had a good roll, Nathan and I started a little "training" session with him. I figured I needed to round out my "middle-aged lady who owns a horse but just does groundwork and doesn't ride" persona, so I figured I'd try teaching Trigger some clicker training. We started with the Jolly Ball, teaching him to touch it with his nose. I had explained the theory to Nathan earlier--at first, we stick the ball right in front of his nose, where he can't help but touch it, and when he does, click and treat. Then we move it just a little further away. It was cool for both of us to see it "click" with Trigger, then for him to test things just to be sure he was right, as I told Nathan he would. Eventually, he successfully touched the ball while it was lying on the ground, not held by either of us, so switched things up and started playing with the much larger horse ball. At first, we just held it still and had him touch it. I tried rolling it toward him a few times, and he backed away, then came back and touched it to earn his treat. Then I rolled the ball AWAY from him, and sure enough, he followed along, trying to touch the ball with every step so he could get his beloved carrots. It was fun for all three of us, but we didn't want to wear out our welcome, so he got handfuls of carrot pieces for his last few treats, I checked his feet, and we put him back.
Nathan also finally finished the sign he's been making--he spray-painted the sign and letters, glued the letters on, sprayed the whole thing with clear coat, both sides, two coats. Other than screwing the cup hooks in and actually hanging the sign, Nathan did the whole thing himself. I'd say both horse and sign are looking pretty good:
I probed all over his back, and he didn't flinch a bit. Of course, he had his face buried in his hay bucket, as you can see above, but I have a good feeling about trying to ride him again tomorrow...wish me (well, SweetPea) luck!