I'm not going to spend time with my husband on his birthday.
Is there a reason you don't want to spend time with him?
I want to spend time with my friend instead.
I think that is mean thing to say. It's good to be honest with your partner about your wants and needs. You should want to spend his birthday with him and also not bribe him to get him to comply with your wishes.
It's not even a bribe I just want him to enjoy his birthday.
I'm sure that he would enjoy it more with you. Even if you want to spend time with your friend, you should consider spending it with your husband.