My work wife threw me under the bus to get a raise at the office. It was hard to realize I couldn't trust her anymore.

• I had a daily ritual with my work wife where we shared basically everything.
• She used the information to try to get a raise, and it felt like she betrayed my trust.

"I think I'm going to get divorced," I told my coworker, who became more like my work wife, on our lunch break. We were sitting in one of the hallways of our company's headquarters, one we liked to call our thinking spot. It featured repeating triangles angling down from the ceiling, all hollow and in a long row. When you looked through them, it was like meditating into a sci-fi passageway.

We'd been coming to this spot nearly every day for months. We talked about work and relationships, about frustrations and joys. She knew all about my marriage struggles; I knew her boyfriend was sometimes frustrated by her overdedication to work.

In our thinking spot, we'd developed a fast and deep friendship. We came to rely on one another for support, regardless of the good or bad situation we needed it for. We were each other's go-to in the office — until it felt like she betrayed me.

I had news about her position at the company and told her

One day, I messaged my friend to come to the thinking spot. She'd been frustrated with her boss, who kept shuffling her around to new projects instead of giving her the raise she was expecting. I'd learned from my boss that her job description was about to shift again, giving her more responsibility with no more money. My boss had told me not to share the information with anyone, but she was my friend. And in that situation, I would want to know as well.

"I know this will annoy you," I told her in the hall. "But please keep it to yourself. My boss explicitly asked me not to share the information. Consider this time to think about it and form a better response for when your boss tells you."

She did not keep it to herself. We returned to our desks, and she messaged me that she was furious. I told her I understood and was sorry but that maybe the notice would be helpful. I asked her whether she wanted to go talk about it more.

I didn't hear back from her for 20 minutes. The next message I got told me why: "I talked to my boss about it and told him I needed a raise or a promotion now. He asked me where I heard the news."

I could feel my stomach in my throat as I asked, "What did you tell him?"

"I told him you told me and that your boss had told you," she said.

I was shocked. How on earth could this person I trusted, this supposed close friend, throw me under the bus like that? It felt like she used me to get a raise.

Then came the final blow. I told her she put my job in jeopardy by doing that, and she sent me a one-sentence response: "You should have expected this."

It felt like she'd used me as a stepping stone for job advancement. Up until this point, I'd assumed all those toxic-workplace stories and advice not to trust your coworkers were exaggerations. I thought my work friends were people I could trust. Perhaps I was too naive.

I tried to make the situation better for myself

I immediately cut off all contact with my coworker. I told one person, a mutual friend, what happened and then never brought it up again. I did not talk to my boss about it, and I never heard anything about it, so I can only assume it never got back to my boss.

From that point on, any work-related communication between me and that coworker was kept in writing. We no longer visited our hallway to chat. I felt like I couldn't trust her anymore.

Later that year, I moved on from that job, and I'm keeping my boundaries up at work.