My dss and dsd are lovely kids but DH is soooo scared of upsetting dsd and she is so super sensitive that noone is allowed to say a word to her which makes her far more annoying
It's the same situation in our house. I think it stems from guilt on his part that he only sees them a couple of days a week and doesn't live with them full time anymore. He lets them get away with all sorts.
Take yesterday for example, they were playing rough and tumble with DH wrestling on the carpet and when DH was laid on the floor DSS2 kicked him in the groin, hard.
It hurt him that badly he had tears in his eyes and couldn't talk for a few minutes.
When DH managed to compose himself he quite rightly told him off and said how dangerous that is and unacceptable, DSS2 went and stood in the corner crying and DH ended up apologising to him for telling him off!
DSS1 today wasted almost all of his tea as usual so DH said if you don't eat at least half of your food then you're not going to be going back on the game. Cue DSS1 throwing himself on the floor and crying, saying he hates DH.
DSS1 still didn't eat the food but DH relented and let him back on the game regardless.
At least once per visit DSS1 will say "i hate you dad" if he's told no or not to do something and DH just takes that and doesn't discipline him.
With our DS though (3) if he's naughty then DH has no problem with telling him off and he doesn't get an apology if DH raises his voice (only ever stern, never aggressively)
I think all of the above massively fuels the annoyance.