The song lyrics are by Snow Patrol, which I don't own anymore than I own Gravity Falls.
There are many ways to tell someone close to you that you love them.
The most obvious, of course, is to just say the simple three-word phrase, but it's not always the most comfortable option, and besides, some people feel that it's a little hackneyed and overdone. Like the song by Snow Patrol says, "Those three words/Are said too much/And not enough."
And it turns out there's lots of other ways of saying it, even if you're two emotionally-challenged old men who have spent decades apart and/or fighting, and are now trying to get to know each other all over again.
Love is spending thirty years trying to find someone even though you didn't part on the best of terms.
Love is working harder than anyone else in the family to get your brother's memories back, by spending hours showing him movies from when you were kids and describing everything you can think of about your past together...and apologizing for all the mistakes you made, while accepting his apologies in turn.
Love is agreeing to finally accompany your twin on the adventure of a lifetime, in the hopes of finding treasure and babes (though maybe you're a bit old/socially awkward to be thinking about the latter).
Love is walking each other through your nightmares and offering reassurance/assistance/hugs if needed.
Love is going together to the cemetery where your parents are buried, and leaving your mother some flowers and a pack of tarot cards (one of you may or may not scrawl 'SUCK A LEMON OLD MAN' on the side of your father's tombstone in bright red marker).
Love is making a nutritious, vegetable-based soup so your brother will eat something healthy for once, and then adding some bacon bits because you know they're one of his two favorite foods.
Love is eating all the soup, not just the bacon bits, and being pleasantly surprised by how good it is.
Love is spending hours talking and telling stories, and learning how to laugh together again.
Love is grudgingly posing for a selfie with the latest monster you two managed to stun by punching it in the face so you can send the picture to the kids, and reminding your twin for the fifty-sixth time to move his finger.
Love is forcing yourself to read your brother's notes on your discoveries until you understand them yourself, and adding your own observations (and the occasional sarcastic comment, of course), because if you could spend thirty years teaching yourself quantum mechanics or whatever, then dang it, you're gonna understand this stuff too.
Love is having a scar contest when you're both drunk, and nearly choking on your drink laughing at your brother's weird priorities when he admits he wears that dumb turtleneck because the scars he can live with, but the tattoos are just embarrassing.
Love is rarely getting into fights anymore, and not letting them last long when they do happen, because both of you have wasted way too many years fighting and you don't want to waste anymore.
Love is leaning lazily on each other while reading or watching something, and agreeing that if he promises not to change the channel whenever you watch boxing and get caught up in encouraging the fighters, you promise not to change it when he watches that one trivia show and spends the whole time yelling out the answers (while both of you view the Black-and-White Period Piece Old Lady Boring Movie Channel as a guilty pleasure).
Love is reminding each other to put on sunscreen in more tropical waters.
Love is occasional prank wars, water fights, and even a pillow fight once when you made a snide comment about your brother's bedhead not getting any better.
Love is sitting side by side at the railing of the boat, fishing poles at hand in the unlikely event that anything is going to bite, with a bowl of toffee peanuts and jelly beans in between you, watching the sunset in contented silence.
