I'm going to tell a guy I've been dating for about a month that I'd rather work on valentine's day than hang out with him even after finding out his elaborate and romantic plan
That sounds really harsh and hurtful. Why are you being so mean to him?
There is no one here to talk to and I'm too busy for this
hurting his feelings like that is terrible. Don't do it unless you want him to break things off with you.
Maybe we will figure out where I'm going to spend valentine's day by the time we hang up.
You should never intentionally hurt someone's feelings. If you aren't interested in someone, you can tell them so with dignity and respect.