I want Daddy! Not you, mom!

Ashton has made it very clear that he is a daddy's boy. Every day when I pick him up from school he asks where his daddy is. Well, yesterday when I picked him up, he started crying and said "No mommy, I want daddy pick me up. You're not my favorite." His daddy phase has been going on now for the last few months and I am wondering just how long this will last. I just tell him "thats ok, I still love you" which usually leads to him saying "I not love you". He does have his Mommy moments every great once in awhile which is nice.