Is it completely impossible to wish your ex a happy birthday without making her or him feel sad, bad, angry, or any other negative emotion?

@eunlee I didn't magically start hating her when we broke up. I'm not going to describe anything about our relationship, out of respect for her, but I don't have hostile feelings towards her. I still care about her general well-being. So I do hope she has a happy birthday. I just wonder if telling her I hope she has a happy birthday might actually make her have an unhappy part of her birthday, in which case I wouldn't want to do that.