conceptually priests went off with the collar and tight black shirts and infodumping about their devotion to their dom and self-flagellation but unfortunately everything else about them is kind of a buzzkill
Al post promised day must have the worst poker face of all time. He hasn't had to think about his facial expressions for like 5 years. It probably takes a while to remember people can see that now and get back into the habit of controlling it.
he's trying to act irritated about Ed fussing over him in the hospital and his voice and body language would really be selling it if he didn't have the biggest happiest smile anyone's ever seen. Ed decides not to mention it and just plays along with his little brother's fake annoyance if it makes him happy.
Mustang shows up and starts antagonizing Ed and trying to goad him into a stupid argument (it's their love language) and when Al interrupts to ask how Mustang is doing he sounds concerned and respectful but he's visibly rolling his eyes and shooting Mustang a look that clearly says "you're the dumbest person I know why are you like this?" Mustang laughs so hard he falls out of his chair.
Whenever people make him mad he tries to stay polite unless they've done something really bad. Flying off the handle is more Ed and Winry's thing, and Al's always had better luck getting things to go his way by remaining civil. But that strategy doesn't work as well when his pleasant tone of voice is competing with the absolute death glare he's giving people over minor annoyances.