Love is feeling out of place when you’re at a party without them. It’s reaching over to grab their hand or turning to talk to them, because you forgot that they aren’t there with you.

Love is knowing you’re invited everywhere your person is invited, even if no one explicitly says so. It’s becoming a packaged deal and sharing friendships.

Love is calling each other by nicknames you created over the course of your relationship. It’s speaking in a language that only the two of you can fully understand.

Love is learning to tolerate that show or sport they’re obsessed with — or maybe even learning to like it — because it’s all that they watch and all that they talk about.

Love is knowing their schedule as well as your own, knowing what time they leave for work and what time they’re going to wake up and what time they’re going to get hungry again.

Love is listening to their favorite songs when they aren’t even around, because you’ve become so used to their brand of music.

Love is sending twelve texts in a row and not even realizing it, because you don’t pay attention to those things anymore. Because you know they aren’t going to judge you. In fact, they’re going to be happy to wake up with so many messages from you.

Love is glancing over to them during a party and knowing if they’re thinking about leaving or if they want to stay a little bit longer.

Love is knowing exactly how much salt they want on their food and how many times they’re going to sneeze in a row.

Love is struggling to fall asleep when they aren’t around, and drifting right off when they’re there for you to hold.

Love is listening to their stories about work, stories that most people would consider boring, and asking for even more details because you genuinly care about their coworkers’ names and what happened to who. Because you honestly want to know what their day is like when you aren’t around.

Love is reminding them to remove their contacts before bed and asking them if their stomachache has gotten any better. It’s taking care of them as much as you take care of yourself.

Love is sharing each other’s cars and clothes without even having to ask for permission. It’s honestly believing that what’s yours is also theirs.

Love is being comfortable enough to feed their pet treats or yell at their their pet for being an asshole, because you feel like it’s your pet too. Like you’re both the parents.

Love is guessing what stories their parents are going to tell over dinner, because you know them as well as your own family. You know their favorite memories, the ones they could repeat again and again.

Love is knowing someone inside and out — and liking everything that you see.

Love is committing yourself to a serious relationship, even though it’s not all fireworks. Even though somedays it’s pretty damn messy.

Holly Riordan is the author of Lifeless Souls, available here.