Jealous husband!

Our daughter is 5mo and has lately taken notice to my son who is 6yrs. She pays more attention to him than she does to my husband and he is soooo jealous!! He calls her a traitor and that she has sided with the enemy. Lol he's all heartbroken and she doesn't even want to look at him. I feel bad but I also feel like he's over dramatic. He even said "Oh well I can work on making friends with our next one on the way." Men I swear!