Very Embarrassed!

However! I do love my partner, he is a wonderful man and I am blessed to have him in my life. Last week, we were sitting on the couch, after a year of dating, and he goes, "yea, she's beautiful, but really annoying. You're beautiful and I love you. There's no comparison." My response was, "You're joking, right?" It was knee jerk, I felt so bad after I said it, I was just caught off guard. How do I make this up to partner? I have since apologized and reciprocated the "I love you," but I still feel bad.