Should I Purposely Forget my Boyfriend's Birthday?

My bf has been stressed out from work and wanted to go out of town together, however I told him that I could not because I was taking a GRE prep course. He got mad because he thought I was just making up an excuse for not wanting to travel so he plans a trip during my birthday. He took off for three or four days during my birthday to go out of town with his roomate. Later on, he apologized once he realized that I wasn't making up an excuse for not wanting to travel. However his birthday is coming up and honestly I dont give two damns about it. I don't even want to celebrate with him, and I want him to feel what I felt l when I was celebrating my birthday without him. So what should I do?