Bit of background: dp and I not living together but he has been staying more often, with a view to moving in. As such, he does have a hand in some discipline. He has a great relationship with dd but slightly strained with ds who may have SEN and can have behavioural issues.
Anyway, both kids were in the house. Ds was upstairs and dp gave dd chocolate. I usually say that if one is offered a treat then I ask the other, doesn't matter if they're not in the room. So dd went off with her chocolate and tried to go into their shared room. Ds didn't want her in their room (a whole other issue) and they had a fight. Dd was crying saying D's had hit her and ds said that she had bitten him. Now if feel as though the way dp approached it was trying to disprove ds eg. "I don't see any bite marks on ds....dd, where did ds bite you?". I'm well aware that there may be some bias at play. Ds is usually the biter and often the instigator but I feel that if we don't know what happened then we can't lead with that bias. It seems a viscous cycle because I feel dp leans towards the negative with D's and so I feel protective. After we'd checked everyone over, ds asked for chocolate like his sister and it didn't feel right to say yes, given they'd fought. I discussed this with dp and said this is why I give equal opportunity for them to have treats at the same time because not being given chocolate would be a punishment for a fight that they both had and would appear unfair. Dp said they were separate issues, that ds could've had chocolate but as a consequence of the fight shouldn't have any. So then we had a back and forth about that. Dp gets really defensive and irritable and I always make a point of not saying that dp is wrong in how he handles things, I tend to say next time I think we should do it differently or usually this is why I'd do it a certain way but he instantly takes it that I'm telling him he's in the wrong.
So do we both have a valid point or is he being unfair, am I being defensive?
I want to try and find a way through this. Trying to strengthen ds and ds relationship isn't likely as ds is rather insular with everyone. I've suggested we discuss our usual sticking points and discuss how we deal with them. How does everyone else handle discipline and day to day squabbles?