The truth about long-term relationships is simple; The lines you once never dreamt of crossing just don’t exist anymore. There was a time when you wouldn't dare mention bodily functions (*GASP* farting) and your hair had to be perfect at every moment. But soon enough, the massive amounts of gas and the empty hairspray bottles add up, and the truth is revealed.
Your once perfect hair, outfit, makeup, etc. no longer has to be perfect.
Talk about a sigh of relief. Honestly, trying to be perfect 24/7 is too exhausting to keep up for more than a month. The first time they see you without all these “perfect” features combined will probably be the first time they see you sick. Not sniffle sick, but "hold my hair while I vomit" sick. Don't worry about this moment. If the person loves you, they won’t care about these things and they'll still see you as beautiful.
Anything that is theirs somehow becomes yours too.
When you go through your closet, you begin to see less and less of your stuff and more and more of theirs. This starts with borrowing a sweatshirt because you're cold and ends with that person not having any left. Slowly, bobby pins seem to find their way from your hair to every possible surface (which I'm sure they just love). The bad side: you lose all your hair ties and have probably forgotten about a pack of bobby pins. The good side: you gain 8 new sweatshirts and 6 new sleep/gym shirts which you'll probably never give back.
Talking about body functions becomes a thing.
When this happens I’m not entirely sure. One day you’re hoping that your natural functions never betray you, and the next you get a 15 minute phone call on their daily deuce. This can ultimately be a blessing in disguise if you let it. You will no longer have to pretend that you are the only angelic being on Earth that doesn't do it.
Their family becomes yours in the best and worst ways possible.
The first family meeting is the definition of terrifying. But after your 10+ time being around these people, they become a second family. They now know EVERYTHING about you. They know about that one embarrassing story from the 4th grade that you made your significant other swear to never tell. This also means you get your hands on pictures from their awkward stage and Grandma's recipes that you can’t live without.
You know this person inside and out, and vise versa.
When you've gotten past all the taboo things, you get to see the real person. Not just the person who loves hockey and drinks more coffee than anyone should, but the person who cares about family (including yours) more than anything and loves you unconditionally.