A/N: So this was originally posted to Archive of Our Own on August 25, 2016. I never posted it here because at the time, there wasn't a Milo Murphy's Law category. But, now there is! Yay! Anyway, this was written before Milo Murphy's Law premiered and is a headcanon where Melissa is the sister of Mandy, Thaddeous and Thor. In this story, we see Mandy's reaction to Milo. Hope you enjoy the story!

Mandy didn't mind have a slightly younger sister. For the most part, Melissa was cool. She was fierce and upbeat, a take no prisoners kind of girl. Sure she never bothered to bust Thadeous and Thor when they were building their annoying creations and never getting in trouble for it, but that was excusable. Busting Thaddeous and Thor was her job, being the much older sister.

What Mandy didn't like however, was Melissa's annoyingly optimistic friend Milo. Milo Murphy. The descendant of the guy who invented Murphy's Law. Anything that can go wrong, will go wrong.

And boy did it ever. Milo was a walking Jinx. Safe's falling all around him, anvils, a Llama stampede...

Though she was pretty sure the stampede was caused by Candace's brothers. Something about Phineas and Ferb starting a Llama Farm and the Llamas escaping for one reason or another. Though how the Llamas had ended up in her neighborhood, she had no idea.

Whatever. It was just another day in her so called life. The doorbell rang and Mandy got up to answer it, regarding the thirteen year old on the stoop.

He smiled. "Hi Mandy. Is Melissa ready?"

"Yeah. She's here." Milo went to step inside, only to be stopped. "Like, where do you think you're going?"

"To see Melissa. See if she needs help with anything."

Mandy stuck her head outside the door. "There's not like a wrecking ball following you or something right?"

He shrugged. "There could be, but I haven't seen one since this morning."

"Doesn't that jinx of yours ever bother you?"

"Nope." He took his backpack off, rummaging around inside. "I see each day as an opportunity for adventure." He pulled out an umbrella and opened it, quickly turning sideways just in time for a swarm of bees to catch their stingers in the fabric. He frowned. "You wouldn't happen to have another umbrella would you?"

"What for?"

A dark raincloud appeared over Milo's head and opened up, drenching him from head to foot. He pointed upwards. "That." He shrugged, then did a quick dance step, reaching into his backpack for a bar of soap and washing his armpits. "Good thing I forgot to shower this morning."

"Ugh. Whatever. You are like, so weird." Mandy rolled her eyes, calling over her shoulder. "Melissa, your Jinx friend is here!"

"Don't call him a Jinx." A thirteen year old girl appeared from behind her, wearing pink tennis shoes, a pink skirt and a black shirt with a short white jacket over it. She regarded Milo with a smirk. "Forgot to shower?"

"Every day is an opportunity for adventure."

"And maybe more soap." She picked up the now depleted bar of soap from the ground, tossing it into the outside trash bin. "Where's Zack?"

"Not sure. He said he'd meet us at school. You ready to go?"

"Yep." Melissa reached inside, grabbing her backpack and an umbrella before following him out of the yard.

"Ugh." Mandy slammed the door, leaning against it. "I don't know what she sees in him."