So this happened via emails:
Supervisor says its ok to take 2 days off after Christmas, ehich gives me 1 week. I know we have some new trainees starting with us. I ask if sup was sure twice and offer to be flexible on my vacation if needed. Sup says its no problem and that all will be ok.
New trainees start and sup realizes that trainees may not be able to keep up and hits me up a week later to see if I was still “flexible.”
My reply: “I offered to be flexible twice and you said no. I already booked my flight.”
Sup now has to work the two extra days after Christmas.
If you work in a big company always get it in writing. Sorry not sorry.