I kept from getting my coworker a cake that she had asked for, for her birthday.
Are you sure she wanted a cake? Did you ask her? How did she react when you didn't get her a cake?
Yea she really wanted to have a cake. She ended up not being happy at all actually.
It is wrong to expect one person to buy a gift for your birthday. It should have been nice enough to go out to dinner with everyone and should be content with that because you can order dessert there.
Can't you just shut your ignorant mouth.
It is fine that you did not buy your coworker a cake. Nobody is forcing you to get her something for her birthday, so for her to expect it is a little rude. There should be no bad feelings when it comes to this incident, however a nice happy birthday would be kind!