AITA for picking up half of a coworker’s shift only to learn she secretly called off the first half?

I agreed to cover the back half of a coworker’s birthday shift as a favor, only to find out she’d called off the front half entirely—something I never would’ve agreed to had I known.

A coworker messaged me two days before her birthday begging me to take the back half of her shift. She said no one else would say yes, and I was her last resort. Our job is exhausting and people rarely pick up extra shifts, but I felt bad and agreed because I thought she’d at least work the first half and then get to enjoy her evening. I even offered alternatives like using PTO or taking an attendance point, but she refused and I reluctantly accepted. On the day of, she was supposed to come in for the front half while I arrived later—but she never showed. When I messaged her, she said she called off sick for the first half.

I agreed to cover only the second half of her shift so she could enjoy part of her birthday—then found out she ditched the whole thing, leaving me blindsided and feeling manipulated.

She insisted she had told me she was calling off (she hadn’t), and when I said I felt tricked, she brushed it off as “none of my business.” She even claimed I volunteered to take the shift, which was false—I only agreed under the condition she would be there for the first half. I tried explaining that I wouldn’t have taken the shift if I knew she was leaving me to cover the entire thing, but she didn’t see an issue.

"I would not have taken the back half if I knew she wasn’t working the front half."

She told me that since I was “helping her out,” it shouldn’t matter whether she got the whole day off. But to me, it did matter—I agreed for a specific reason. The conversation went in circles, so I dropped it and just worked the half-shift I’d promised. I’ve since told myself I won’t be doing her favors anymore. Still, she and her roommate (who I work with daily) both seem annoyed with me, and I’m left wondering if I mishandled the situation or if she simply took advantage of me.

"She said it was 'none of my business' and acted like I offered to take the shift."

Other coworkers mostly understand why I’m frustrated, though a few think I shouldn’t care whether she called off the first half. I’m not making it a workplace issue—I just won’t go out of my way for her anymore. Still, the tension lingers, and I’m curious how others would see the situation.

🏠 The Aftermath

I worked the back half of the shift as promised, even though it no longer felt like a fair exchange. Afterward, I quietly decided I wouldn’t be taking any more of her shifts.

She and her roommate seemed annoyed with me pulling back, despite the fact that she’d misled me about her plans. The tension at work hasn’t erupted, but it’s definitely there.

For me, the real consequence is realizing that what I intended as a favor was taken as an opportunity, and that trust between us took a hit I’m not sure can be repaired.

"I felt like I agreed to one thing and ended up doing another."

It’s disappointing that something meant to be kind turned into a situation that made me feel used, but I’m moving on and simply adjusting how I handle future requests.

💭 Emotional Reflection

This situation wasn’t about policing her birthday plans—it was about being upfront. I agreed to help her under a specific premise, and when that changed, the honesty should have changed too.

Technically, the shift still got covered. But emotionally, it felt like my kindness was taken advantage of, and that’s where the frustration sits. A simple conversation upfront could have prevented all of this.

Some will say a favor is a favor, and others will say expectation-setting matters. Both can be true, but miscommunication—or selective communication—can turn small favors into big frustrations.

Here’s how the community might see it: