Since your daughter is closer in age to her, try to set some activities for the two of them (that will occupy their time)
You just feel that he is giving her more attention when she is there. That is understandable, yet, harmful to you and the relationship. She is a child and he had explained that he does not see her as much. Daughters and fathers need to bond. She is lucky to have a dad like that. Many kids never establish a good relationship with their fathers and you would not want to seem like someone who is preventing them from sharing some quality time.
On the other hand, you can let him know that you are ok with her visiting but that you also would like to do things with him. If she is only there for a short weekend, then you can try to be flexible (after all, you and him have the rest of the week with each other)
Try to do some things just you and the girls (take them shopping, to the movies, etc) for a few hours. She may learn to try and give attention to you and your daughter which in return will open some space for you and him.