Husband pissed over Facebook friend request

Last night my ex boyfriend(from 13 years ago) sent me a friend request on facebook. I told my husband I would always be 100% honest with him especially with social media. I always show him any requests and rarely ever approve guys. Well he lost it. First he accused me of never telling him about this ex and finally he remembered I had. Then he was mad because he tried adding me. He said I must have done something to make him want to add me. I haven't talked to this ex in years! I deleted the request but he's still being a dick to me. Wth! He is friends with his ex on social media and even "likes" 9 out of 10 of her posts... how the heck is this even fair to me!