Just need to vent...

So, hubby had three kids from a previous relationship, two boys and a girl ages 13, 11 and she is 7. I have a boy from a previous relationship, also 7 (they are three days apart). We have one boy together, 2 and are pregnant with another boy.

Hubby and I have a wonderful relationship, we don't really fight; if anything we may disagree but that is the extent of it. We are currently having problems because we are on Vacation, and our daughter has been disrespectful at EVERY TURN... When we have all the kids together - a majority of my time is spent with the younger ones, not to mention my daughter has Cystic fibrosis, so her medical needs are consistent throughout the day. Well I tried talking to hubby about her misbehavior, and how she blatantly distespected me over her medical treatment (although she KNOWS she NEEDS it) his response 'you hate my daughter'.... Her biggest problem this week, has been why? Why? If she is told no, not right now, whatever it is - her first response is why, then she will ask for something else... True example:

Daughter: Daddy, can I have more snickers

Hubby: no ma'am 

D: why?

H: because I said no

D: then can I have a piece of cake

H: no, we are about to have dinner

D: but I am hungry

H: dinner is almost ready

D: but I am hungry now, can I have another piece of chocolate

H: Daughter, I said not now, you've already had more chocolate than you need

D: why?

Then he gives it to her anyway... She comes back, not even five minutes later and asks for more, he tells her no, she asks why, and he taps her butt. Now I say tap because he did not really smack her, more of a warning of anything... She starts pouting.... So he starts to talk to her to get her to understand why she was in trouble - then he starts playing with her without even finishing the convo.....

About 5 mins pass and she walks up and asks for more chocolate, again... He says I just told you no, she asks why, then begins laughing.... 

I tell him, she does NOT take you seriously because you just played with her, his response, ' well you let your son get away with everything'.... He starts naming off a few things my 7y/o has done in the past, and all I can say, 'so it's only okay if he has a vagina?'... Everything he named is old, for one, and for two, our daughter does that and some on a daily basis...

I'm losing my mind here )':