Honestly, Scott should just be grateful that Alex doesn't have a leash to taunt him with. In fact, he probably could have an entire arsenal of crap dedicated solely to the purpose of being an ass to his brother. Though, maybe Alex was lucky that he didn't, as Scott might have actually wound up mauling him by that point. But that's what rapid healing is for, right? So really, it's still an idea on the back-burner for later development.
When the gesture was made and Scott started moving again, Alex exaggerated a sigh and started to follow. Slowly. He had to stop himself from calling him Lassie and asking him where he was leading him, or if Jean had fallen into a well. Apparently he was in that annoying little brother mood? Or he was just displacing his annoyance with Lorna on Scott - which is more likely. Yes! He was petty sometime, leave him alone.