Once a relationship establishes a pattern, it’s extremely hard to change it.

You know how it works. Other than the close friends and family you’re completely comfortable being around, everyone else exists in the narrow parameters within the context of your life. You generally see them in a specific setting, interact with them in a certain way and then part ways before things stray out of their natural order and get awkward.

These interactions can range from a brief smile-and-nod to casual sex. I, for example, have one relationship with a friend that is based entirely on physical threats. Her name is Amy.

Of course, the threats aren’t real. The two of us merely share an offbeat, uncensored sense of humor. We mutter obscene jokes under our breath while our broadcast journalism professor drones on about whatever we’re supposed to be learning in class.

Every week, while sitting next to her, I’ll turn to my friend and say something crude: ‘Amy, I’m gonna kick you so hard in the balls that some of the guys in here might actually start thinking you’re a girl.’

On cue, Amy will turn her 5-foot-2-inch frame, stare straight at me with her big, bright eyes and reply, ‘Danny, I’m gonna shove this pen so far down your throat that you’ll poop ink for a week.’

We continue exchanging threats until one of us (usually me) breaks down laughing. Class eventually ends. She goes back to her sorority house, and I return to my place on Ostrom Avenue.

Then, last week, everything changed.

I had to cover a story in Liverpool, N.Y., for a class newscast. Since I have no car, Amy drove me there.

As we cruised down New York state Route 690, everything seemed normal. I promised to roll her into a ball and punt her off a bridge into Skaneateles Lake. Not missing a beat, Amy described to me — in detail — her plan to forcibly remove my limbs and feed them to her friend’s Chihuahua.

While I prepared a clever response about FedExing her to a cannibal tribe in Papua New Guinea, sirens blared from behind us. A police car appeared in Amy’s rearview mirror. We were getting pulled over.

All of a sudden, my hilarious, steel-faced friend burst into tears, sobbing hysterically as I coached her over to the highway shoulder. Light-hearted jests gave way to panicked cries and unintelligible screams about losing her car privileges.

I felt terrible for her, but I felt even worse that I couldn’t do anything about it. My first instinct wasn’t to comfort her, or even try to calm her down. It was to joke with her like I always had. The words nearly tumbled out of my mouth: ‘Hey, Amy, way to go! I wonder what they’ll do to you in lady prison.’

I couldn’t bring myself to say it.

Normally, we feast on each other’s humiliation. But seeing her in such a state made me realize that she was more than just the only person on campus twisted and perverted enough to joke around with me. Somehow, through our crude humor, I had come to care about this girl too much to add to her misery with an ill-timed jab.

Eventually, I managed to say a few comforting words to her. I think they helped. She stopped crying a few minutes later, and soon we were joking around like usual.

Still, no matter how hard I try, I can never look at her the same as I did before. She now exists outside of her normal context, as a good friend who does more than merely threaten me with bodily harm.

But I’m feeding that Chihuahua to my roommates, just in case.

Danny Fersh is a senior broadcast journalism major and his column appears every Wednesday. He would like to give a shout-out to Amy’s freshmen and thank AZD for giving him the time of day. If you find ink in your feces, contact Danny via email at dafersh@syr.eduand follow him on Twitter at @fershprince.