I’m an only child, DH is one of 6 so I’ll give it to him sibling dynamics are more his area of expertise than mine. We have 5 dc.
DD and DS are under a year apart (9&10) are are extremely competitive with each other.
They are both very athletic and do several of the same sports. They will work the hardest at a sport they don’t particularly like just because it’s the sport the other one likes the most or is doing better at.
Dh encourages/ doesn’t discourage the competitiveness. He often arranges or at least judges competitions between them, who does the best, the most or the fastest whatever
And sometimes gives them both challenges, who ever can do X gets Y.
It’s not always physical, it’s just as often who has the tidiest room or who can pick up the most rubbish from the beach. Beating the other one is their biggest motivation in life and I hate it.
They’ve thankfully grown out of physically fighting but they can be verbally really vicious towards each other and arguments can last for days. I immediately want to separate and if necessary punish when any nastiness happens but dh is very lax and thinks leave them to it, they’ll sort it out and makeup.
They are at all other times the absolute best of friends, they play, comfort and help each other daily, will be first to defend the other and are each others biggest cheerleader at separate activities.
Is this normal or harmful? Who is unreasonable? DH for not caring enough about this or me for caring too much about it?