Don't be Suspicious, Don't be Suspicious
AKA "Danny Fenton is living the Wayne family as an emergency foster. He's trying to be lowkey and Totally Normal, cue the misunderstandings and shenanigans." DPxDC prompt idea loosely inspired by this post by dcxdpdrabbles
The first time is, unfortunately, the most embarrassing. Danny's only lived with the Waynes for maybe four months but he's gotten comfortable enough to establish a routine. Danny waits until they go to bed around 10pm and then facetimes Tucker and Sam to practice his Phantom powers. It's a Thursday night and Sam's at a gala with her parents, so it's just Tucker and Danny - they're trying to figure out if Danny could grow an extra limb while in human form.
Danny's got Tucker on his laptop on the bed, shirt off and trying to focus on growing an extra arm. It's difficult and he's groaning about not being able to do it, Tucker encouraging him from the speakers.
And then there's a knock on his door. And then it opens, right as an arm sprouts from Danny's side (thankfully the side facing away from the door). He briefly hears Tim's concerned voice ask, "Danny? Are you-" while Tucker's still talking, but Danny is already shrieking in surprise. He's throwing a pillow at the door, slamming his laptop closed, scrambling under the covers, meanwhile Tim is apologizing profusely behind the closed door.
The next morning, Danny's third arm is gone and a sick sense of dread replaces it. (This is it. He's going to be kicked out, he's going to be turned in, experimented and dissected-) Tim hesitantly approaches him after Mr. Wayne and Damian finished breakfast.
"Uh, I-um. Just wanted to say that... it's okay, y'know? If you're... I mean, I'm bi and Bruce is really supportive. So, you don't need to hide your... friend. From us. If-" Tim stumbles, face flushed and looking anywhere but at Danny. And it dawns on him that Tim thinks he and Tucker were doing something else last night. He's so relieved that Tim didn't see his mild body horror episode that he just dumbly nods and thanks him. (The family don't treat him differently after that, exactly, but they share cheesy looks whenever Danny mentions Tucker in passing.)
The second and third time actually happen because Mr. Pennyworth is catching Danny as he's leaving the manor. It's a Saturday night and Danny is going to the movies with Danielle (and crimefighting after. Dani wanted to go soup some scary clown and Danny is super down). Mr. Pennyworth embodies the quintessential Disappointed Father as he asked, "Master Danny, I presume you discussed your late night escapade with Master Bruce?"
Danny's "uh, yeah" is super convincing but somehow Mr. Pennyworth doesn't fall for it. The British gentleman gently chides, "Young man, I have lived through several generations of children sneaking out of the manor to attend parties, tussle, and meet their paramours. These old man's eyes do occasionally still see."
Danny sheepishly apologizes and spends the next 10 minutes trying to convince Mr. Pennyworth that he really is just going to the movies with Dani, then the next 20 after that refusing the suddenly ecstatic older gentlemen's offers of snacks, rides, and a spare room for Danny's "cousin". He smiles shakily when Mr. Pennyworth gives an approving nod and says, very good, sir. It's good to see a boy enjoy such normal hobbies.
(Danny doesn't feel too bad since it doesn't sound like anybody figured out what he and Dani did. Apparently, the Wayne family groan about somebody named Jason when they find out the killer clown was hospitalized.) The second time went similarly, albeit it was Sam who wanted to visit Dr. Pamela Isley's home to discuss some kind of eco-friendly business. Danny was too busy talking with Dr. Isley's wife, Dr. Harleen Quinzel, to pay attention.
Danny keeps trying to Act Normal. Hides his exhaustion, his late night practice with Sam and Tucker (who he's still pretending to be in a relationship, much to Sam's glee), and his crimefighting. He doesn't go out as Phantom - he's changed his MO, his suit, and keeps mostly invisible. He patrols areas that are really, really bad, like Crime Alley, that he knows the bats tend to avoid. He's earned the (unfortunately, very astute) moniker as Gotham's new meta vigilante, Casper.
So far, he's had to make excuses to the Wayne family for his recent bout of exhaustion such as: low iron (which Mr. Pennyworth immediately force fed him about 8 pounds of spinach with every meal), insomnia (Tim sympathized with and gave him what might actually be an illegal dose of melatonin gummies), and as a last ditch effort... he's apparently doing drugs. Mr. Wayne pulled him aside and gave him an extremely uncomfortable DARE lecture that resulted in Danny practically melting through the floor.
It's fine. Danny's making it work, doing his best, and his foster family is thankfully super oblivious.