1. You have those “silent dinners” you always feared.
When your love was just blooming and every evening out was officially the Best Night Ever, simply because you were in one another’s intoxicating company, you used to look at those couples with pity. There they were, sitting under the unforgiving fluorescent lighting of some Chinese Buffet, wallowing in their own regret and complete disinterest in initiating conversation. They would graze on their General Tso’s, sigh occasionally, and mostly just stare off into the distance — presumably to reflect on a version of their life which didn’t involve being trapped in a relationship with someone they could so scarcely conceal their disdain for. “Let’s never be them,” you would say, going in for a passionate kiss which reaffirmed your youth, beauty, and infinite attraction to one another.
Now, the two of you make it all the way to the shared dessert course at California Pizza Kitchen without muttering so much as a “Do you know where the bathroom is?” The thought that you may have become that couple briefly crosses your mind, but remedying that with some conversation is just beyond your ability to manage.
2. The sex has become so non-existent that you no longer even address it.
You used to fuck like rabbits, then you made love like lovers, then you touched like partners, then you slept on opposing ends of the bed with a book or a laptop as your most fulfilling company, and extended physical contact only when you pushed them onto their stomach if they snored too loudly. You’d bring that up, but then they’d probably want to try and have sex to fix it, and you’d rather just watch television and eat leftovers.
3. You find yourself lying for no reason.
It would seem ridiculous to lie when someone asks you how your day was. You could easily just say, “I don’t know, I had kind of a tough time at work, and I got a new shirt on my lunch break, and then someone let the door slam in my face getting off the subway.” There’s no reason to lie about that. But when you are living amongst the ruins of a rapidly decaying relationship, further discussion must be avoided at all costs. You are not trying to get into some grandiose explanation about all of the shitty politics that are going on at work when you could just as easily drown out the existence of your partner with a little music and a glass of wine. Saying “fine” to everything is a desirable substitute to interactions in most instances.
4. The topics of conversation always stay superficial.
“How is your pasta?”
“It’s really good, you wanna try some?”
“I’m alright.”
“[Continued silence]”
“It’s raining again.”
“Shit, I forgot my umbrella.”
-Every Bad Relationship ever.
5. It’s best when you buffer yourselves with other friends.
As the idea of spending extended periods of time alone with each other is becoming increasingly unpleasant, it is always best to include several friends into the mix when planning a night out. While that does mean that you run the risk of being that awkward couple who starts bitterly arguing of something that is clearly greater than this particular evening’s happenings, it does mean that you aren’t going to be left with one another for company and therefore stand a chance of having some actual fun.
6. You start fights for the most absurd reasons.
“You incompetent asshole, you are loading this dishwasher wrong on purpose. Are you that fucking incapable of doing something right that you are like, ‘Oh, whatever, I’m just going to stick these knives blade-up so she’ll stab herself while trying to take out the plates which are clearly covered with dried barbecue sauce! That’s a sufficient substitute for being an adult who puts a minimum of effort into shit!’ You are just like your stupid mother, and I’m not going to clean up after you like she does. I actually have a job.”
You don’t think you’re the kind of monster who would say something like this over an improperly-loaded dishwasher, until you’re in the throes of a terrible relationship, and then venom just starts spewing out of every pore like you’re some kind of emotionally abusive colander.
7. Everything starts to seem like an exit.
That barista was nice to you, maybe he will run away with you into the sunset! You two are fighting again, maybe he’ll gather up the courage to cut this off so you don’t have to! Maybe an owl will come through our kitchen window and let one of us know we’re off to Hogwarts so we are basically forced to break up with our home-partner because we all know that shit won’t last wizard dorm life.
8. All your favorite qualities are now mild irritants.
“I used to think that gap in your teeth was adorable, but now I realize it is merely an aqueduct for the endless rivers of shit which are constantly careening out of your ignorant face! Get thee to an orthodontist post haste, your mouth is making me question decision I’ve ever made in my life.” 
