Surprises can make gifts more meaningful, but when one person is left out of the planning, the surprise isn’t always a pleasant one.

What started as a shared birthday gesture turned into an unexpected expense and an even bigger argument between sisters.

Read on for the full story.

AITA for refusing to pay for a gift my sister bought for our dad without including me?

Me (23F) and my sister (22F) have a close but often argumentative relationship.

She lived with me in my university city while working, and I helped her get a job at my workplace.

She has poor financial habits — excessive shopping and asking for money at the end of the month — and my dad had to pay her rent, despite his financial struggles and my mom being unable to work due to health issues.

But regardless, when her sister moved back home, she dropped everything to help.

After a few months, she abruptly moved back home, and I helped her clean and pack.

She later stayed with me again for work, during which I paid for food, skincare, and even clothes, while also lending her my bus card.

On New Year’s Day, we went home to celebrate our dad’s birthday.

I wanted to buy him a gift, but my sister and mom discouraged me.

So she came up with a plan with her sister, but things quickly got messy.

At dinner, I finally got him to tell me what he wanted — earbuds. I told my sister we could buy them for him, and she agreed.

Two days later, while I was deep-cleaning my parents’ house, my sister went to the gym. She came back with a gift for my dad but hadn’t told me.

She handed it to him and initially said it was from her, then corrected herself and said it was from both of us.

She can’t believe her sister would go behind her back like this.

I was upset because she hadn’t included me in the process yet expected me to pay half.

When I told her I felt excluded, she dismissed my feelings, called me childish, and insulted me — saying I was lazy and commenting on my appearance.

Frustrated, I told my family I’d leave the next day and needed space from her.

The rest of her family didn’t seem to understand her point of view either.

My mom sided with her, saying it was fine because she had claimed the gift was from both of us.

AITA for refusing to pay for the gift?

This was some seriously shady behavior from her sister.

What did Reddit think?

This commenter encourages her to enforce a zero-tolerance policy with her sister.

It’s high time her sister start thinking about someone other than herself.

With enough persistence, setting strong boundaries does work.

This commenter seems to think this is just her sister’s MO.

She thought they were sharing a thoughtful moment, but instead, she got stuck with a bill.

Some presents come with a bow, but this one came with strings attached.

If you thought that was an interesting story, check this one out about a man who created a points system for his inheritance, and a family friend ends up getting almost all of it.