This little shot was inspired by my mom's favorite joke. I did in fact change a couple things about it to make it work but the basic structure and punch line is still there.

A math professor who becomes tired of his marriage with his wife.

To say that Erwin, a math teacher at Trost High, was unhappy with his marriage was a lie.

However, it was not a lie to say that Erwin was unsatisfied with his marriage.

To be completely honest, he loved Levi. He truly did. He wanted Levi to be happy and have only the best. The only problem was that neither of them were interested in each other anymore. It must have been months since the last time they actually fucked, and even then it was lackluster and missing all of the passion they'd had for each other in the beginning of their relationship. All of the fun that came with being in love has slowly seeped away the longer they were together.

To this day Erwin still isn't sure what happened.

Was work too demanding? Was life just getting in the way? Were they just getting too old? Was Levi getting bored of him? Were they just never meant to be?

Thoughts like these were usually what plagued Erwin these days. He'd never even talked to Levi about these thoughts. They both knew this marriage was falling through, but talking about it would only make it that much more real.

"Um… Mr. Smith?"

Erwin had to force down the excitement that sparked from in between his legs at the angelic sound of his teaching assistant, Armin Arlert. The blonde beauty stared at him curiously before Erwin realized that he was awaiting Erwin's response.

Clearing his throat, Erwin replied, "Yes, Mr. Arlert?"

"Do you need me to stay behind and help you grade homework?" Oh this boy was perfect. So kind and considerate and absolutely adorable. Alright, don't be too eager for his help. That'll just come off as creepy.

"You may if you'd like to, but don't you have clubs to get to? Friends to hang out with? Whatever you kids do these days?" Erwin silently pleaded with the gods that Armin would say no.

"No." Erwin mentally jumped for joy. "My friend ditched me, and I figured since I was already here that I would help you. You probably want to get home sooner anyway." That was probably the exact opposite reason for Erwin wanting Armin to help, but he didn't have to know that.

"Well, that's very kind of you. Thank you, Mr. Arlert." Erwin pulled out his stack of homework that still needed to be graded.

"You can just call me Armin, you know. Most teachers do," Armin teased, grabbing part of the stack. He had that coy little smile of his that always tried to wilt what little self-control Erwin had left.

'Only if you call me Erwin. And by "call" I really mean "moan and scream while I have you pinned beneath me"' Erwin thought, and then mentally smacked himself. '…I've taken too much after Levi these past years…'

But perhaps this is exactly what was supposed to happen. Maybe getting some fresh meat would actually be healthy for Erwin and Levi's marriage. After all, people cheat on each other all the time. At least the drama would spice things up.

"So how's your husband, Mr. Smith?" Armin asked part way into grading. Only, it sounded a bit… too innocent, and Erwin caught onto that.

"Not as great as he could be. We're going through a… rough patch." He sounded far too sultry for a man supposedly suffering from a tough marriage, but that's exactly how he wanted to sound.

"Oh no, I'm so sorry." There was no real sympathy in that voice. "Is there anything I can do to make it better?" Armin leaned forward onto the desk, bringing his face closer to Erwin's and looking completely fuckable in Erwin's eyes.

"Well, what would you be willing to do?"

Armin leaned farther across the desk, his face mere inches from Erwin's. His breath tickled.

He whispered, "Anything you want me to."

Now, that's not to say that Erwin felt good about the fact that he was going to cheat on his beloved husband, Levi, and he certainly didn't feel good about the idea of doing it behind his back.

So Erwin left a note for Levi.

My Darling Levi,

You are 39 years old and have been with me for the past 15 years, and, as you may have noticed, I have grown tired of our relationship. I just simply am no longer and will no longer be satisfied with you. It's not your fault. But seeing as I still love you, and seeing as you have been a wonderful husband to me despite our problems, I feel that it's only right to tell you that I will not be home tonight. Instead, I shall be at a local hotel with my 21 year old teaching assistant, Armin. Don't wait up.

With Love,

Erwin

Although, despite how bad he felt before, spending time with that adorable assistant of his was completely worth it. That kid had a good set of lungs.

The dread only started to creep up on him after he'd dropped the boy back off at his apartment.

What would Levi say to him? What if that completely ruined their relationship? He didn't want to completely cut it off with Levi and be on bad terms with him. He still wanted Levi in his life at least as a friend. Curse those totally fuckable teaching assistants with good lungs and tight asses who knew how to seduce the teachers they assisted.

Only…

There was no one at home when Erwin opened the door.

Not even the classic "all the lights are off making it seem like no one noticed you were gone until you walk inside and someone's sitting in the living room or something and then turns on the light and catches you red handed" move… That really needs a better name…

Instead, Erwin found another note right next to the one Erwin had left for Levi.

My Not So Darling Erwin,

You are also 39 years old and have been with me for the past 15 years. So of course I fucking noticed. I too have grown tired of our relationship, because I also am no longer and will no longer be satisfied with you. It's 100% your fault. But, seeing as how you ever so thoughtfully let me know that you'd be fucking your assistant tonight, I felt that it was only fair that I let you know that I will be at another local hotel with our 21 year old pool boy, Eren. And as you know, being a math teacher and all, 21 goes into 39 A LOT MORE than 39 goes into 21.

Don't wait up.

Levi is a total bottom in this fic by the way. Which is why 21 (Eren) is going into 39 (Levi). Just in case you all were curious or wondering about that.

Hope you enjoyed that crack shot! :D

:)Puppy-Chan(: