Boyfriend's family causing strain
My boyfriend of one year and I moved in together about 6 months ago. The relationship was still new and I am still going through my divorce (it had been over a year when I started dating my current boyfriend). Things changed drastically but my daughter is dealing really well with the transition. His children on the other hand are not. My main concern is that when it comes to his children he would do anything for them, including allowing them to do things he would NEVER let me allow me to allow my daughter to do. The list (his eight and 13 year old daughter still sleep with him when they stay over, they can eat sweets no matter how much healthy dinner they have eaten, they get money when ever they want and their mother literally lives off of him (he pays for the home they live in and is still also supplementing by buying school supplies,sports equiptment and clothing when he can). Just recently the eldest of his daughters won't stay with us for something I "did". I don't have any idea what it could be but the youngest just recently came to our house and had a huge attitude problem (she told her father that he and her were supposed to go out to eat and I could not go out with them, she then proceeded to tell him that he would not punish her for what she said and would forget about it by the time we got home, then stated when we did finally get home that "see I told you you'd forget"). Her father quickly diffused the situation but I see it as a sign that things are not getting better but getting worse. He said it wouldn't be easy but to disrespect me and her father like that was uncalled for. He insists on still keeping his daughters happy by sleeping with them when they stay with us, allowing them to eat what they want (because they ate at moms)and behave as they want to when many times it involves stepping on my daughters toes. Also any time they are here I cannot even talk to my boyfriend without them interrupting or needing to be in the middle. I cannot sit next to him on the couch or when we are out nor can I show any kind of affection towards him (hugging, hand holding, not kissing.)
I know I will never be number one and I completely respect their relationship but what can I do to make sure that my family gets the respect that we deserve? This is a long haul relationship and when his children are not around we could not be happier, I don't like to blame our problem on them but it seems true. I have tried being a friend to his kids but that only ends in me getting taken advantage of. How do I approach this carefully and tactfully?