GUYS Why would you save Christmas Cards?

My boyfriend always (secretly) saves Christmas cards from girls if they write ‘love from’ on them. If the card is addressed to both of us then he won’t save it. It really upsets me. I don’t know why he does it. I thought we had something good. Am I not enough for him? I know this sounds like I’m a little girl with a silly young boyfriend, but he is 43, which makes it all the worse. Please give me your opinions, this is serious for me and it really does hurt me. What is wrong with me? Or us?