Husband celebrates his ex-girlfriend's birthday. What should I do?

This is normal. Getting married doesn't mean everything is yours. Maybe I married you because of family pressure or other reasons. What can come together is not necessarily the deepest love, which makes him unforgettable. What a relationship fears most is that it has no passion. It's only your duty to be nice to you and your family. From your account, we can know that your husband is a nostalgic person, and there must be a great reason for his separation from his ex-girlfriend. You should talk to him. Guide him to let him speak out those unwilling and wronged. You'll know what's going on, and then prescribe the right medicine.