You're six when you get it. You've seen them act like this before, sure, but you have never really understood until now.

They're in love. Seriously in love.

It's gross sometimes. They don't think you're looking when they cuddle on the couch behind you as you watch The Lion King for the millionth time. When you turns around, Mom is kissing Dad and his hand has ruched up her shirt so that a pale strip of skin is bared. His fingers are smoothing over that little line of Mom's side and, yeah, it's gross.

"Da-ad," you whine. "Watch the movie."

Mom only smirks, tugging her shirt back down into place. "Yeah, Castle. Watch the movie."

A second later, you are scooped up onto the couch, snuggled in between your parents as Simba sings along with Timon and Pumbaa.

But other times, it's pretty cute.

Like when Dad rushes after Mom with coffee in a to-go mug in one hand and a scarf in the other, shouting about needing to be warm in this weather. Or when you and Dad surprise Mom at work with her favorite burger and sweet potato fries because Dad said she was having a tough day. When Mom makes Dad dinner and puts it under tinfoil because he's stuck in a writing craze so that he'll have food when he finally emerges from his study. Sometimes Dad steals sips of Mom's coffee, insisting that he needs to make sure it's safe before she drinks it even though it makes Mom roll her eyes.

And they've said it before. Dad says it more often than Mom but you finally understand that they both mean it. Every time. Even when Dad shouts "God, I love you, Beckett, but your job drives me insane."

But your favorite time to hear those three words is when Dad has you in his arms, opening the door to Mom just as she gets home. When Mom tiptoes up to touch her lips to Dad's, whispering "I love you" before framing your face with chilly palms, kissing your nose.

"Love you, too."

You're only six but it's then that you realize that you want to be Mom. But only if you get a Dad too.