Bart wasn't sure if Wally was over-acting for his benefit or if he actually was bothering to scream like that because it hurt. He kind of doubted the last one, since ( he knew from all too recent experience) when it hurt bad enough that you wanted to scream, you usually weren't screaming jokes.
Then again, they'd always been an odd family.
To keep Wally distracted and to try to get him to stop yelling right in his ear (gawd Wally), Bart turned as much as the nurses would allow him and started flicking the tender skin of Wally's exposed earlobe every time he screamed or didn't do what the doctor directed.
"OW! My pancreas!" FLICK. ...sugar-free, cause that's just insulting FLICK. I don't need stitches! DOUBLE FLICK-FLICK.
Pretty soon he was going to resort to grabbing Wally's hand and making him hit himself.
"Do you want some cheese to go with that whine?" He grumbled, his sense of humor thankfully still intact. "I'm the Flash and I like to scream like a little girl." Kid Flash teased, adopting a high pitched voice in approximation of a little girl, "And not even like a badass little girl- like a tiny scared puppy. I tell everyone else to shut up because I know what's best for them and but when it's my turn? Noooooooooo."
"Are we going to have to separate you two?" One of the nurses asked in her Mom voice, glaring at the two far-too rambunctious speedsters.
"Nooooooo." Kid Flash promised... snapping one hand out at superspeed to flick his "mentor" in the ear one last time.
Clearly, at least one of them was starting to feel better.