Need to understand

Whitney
So my boyfriend and I just got into it again. This time it's over the fact that I brought my ex. He asked me when is his birthday. I told him it's either the 16th or the 17th of December. Then I said no it's the 16th because my ex bf is the 17th. He said it was disrespectful because I brought my ex up and I couldn't remember his birthday without remembering my ex's. I didn't mean anything by it. I just want wanna understand from a unbiased perspective.