So for the last year or so I've had a stepson a lot older than my Dd she's just turned 3.
We have him twice an week after school and every other Friday night over night.
Recently we've noticed his becoming very competitive and annoying towards her, I don't know if it's a brother sister thing but it's starting to annoy me us adults, at dinner times he's very competitive about how much he's ate or DD has, most of the time he'll ask if he's got/ eat more than her he gets very upset to the point where he'll cry if DD finishes before he does, tonight at dinner time he took her plate away while she was sill sat at the table because she was having a drink instead of eating which resulted in her biting him ( before the parent police come out we told her off straight away and told him off for taking her plate), she's very protective of her food we just don't know why he's becoming so competitive with her his dad has spoke to him about this multiple times but it doesn't seem to be getting any better, is this a normal thing and something that just happens?