AITAH for not allowing my step daughter to go on a trip my father had prepared for my own daughter?

Me (30F) and my daughter Rose (15F) have been without my husband for many years after his passing. My daughter had always had a special bond with her grandfather in replace of her father’s passing, he had always been there with us even through the grieving and hard times. They would spend some weekends together going to a lake house my father had owned, using jet skis, boats, and what not.

Well I ended up falling into an amazing relationship with my now (32M) husband for 2 years. He has a daughter Lilly (16F) who I love just as much as my own daughter. Shes never really met my father since he lives quite some ways away. The one time they’ve even came in contact is when he had came over for dinner, but she sat upstairs in her room all night not even giving him a hello. No problem, maybe she wasn’t ready? Who knows? I brushed it off.

Well last weekend my father calls me and asks my daughter Rose if she would like to go to the lake house that following weekend, and to bring some friends. She was so excited and immediately said yes. My step daughter walked in and asked what all the noise was about, when my daughter told her she asked almost immediately if she could come and bring some friends. Rose didn’t want her to come, even knowing she doesn’t even know my dad. I told Lilly I would ask.

When I called my dad the following evening to ask, he told me respectfully no, he doesn’t exactly know who she really is and how he would like to spend time with his granddaughter. I told him that’s absolutely fine. When I told Lilly that my dad had said no, she threw an absolute fit, yelling and calling me names all over the fact that she wasn’t aloud to go to this lake house.

Well, Lilly ended up running to her father crying. My husband thinks it’s unfair and can’t see exactly where my father is coming from. But I don’t know, AITAH?