My biggest worry when I was expecting my second DC was that my first would get upset and be jealous. Well to my relief she wasn't at all in fact she barely paid him an attention at all 
Anyway to my surprise DS my second born is now 11 months and is jealous of DD. He goes mad if she sits on my knee. He also got very upset when I held my sisters baby last month before lockdown.
Is this quite common with second born? You just always seem to hear it about the first feeling pushed out. Also any advice on how to tactical this as I really don't want it to develop and I want them to have a good relationship?