Is jealousy normal between siblings with their mom?

I have a large family that consist of me and my husband and our three kids: Nevan 6, Payton 3, and Chloe who's 5 months old. Now, Nevan gets along really well with little Chloe but he gets in a lot of fights with Payton. Especially when me and Payton are hanging out together. When he sees us together he goes to his room and doesn't speak to Payton all day, which hurts his feelings. My husband says it's because he's jealous. I was wondering if this happens a lot since I'm expecting another boy soon and does it pass? Or does this sibling rivalry continue?