Toddler suddenly dislikes my parents

Anyone can relate? I can’t figure out what happened because every time my parents are around I am always around too. I’ve never left him alone with them and I’ve never seen them do anything besides express their love and show affection. It’s concerning me now because what if he senses something about them. When I take him to my in-laws he’s the happiest kid ever- just with my parents he acts very upset and cries. & he hardly ever cries at home or anywhere else. He is genuinely a very calm and happy kid.