Drake had waited patiently for his chance to mate with Charlotte, his sister in law's sister. Things kept getting in the way until he took matters in hand. Now she would be in his territory where she would be under his control.
Charlotte wasn't completely comfortable around drake but she could handle him if he got out of line. He might think he could charm her into his way of thinking, but she wasn't going to let him get by with a thing.
When white wolves are involved, it's never easy, but it's always worth the trouble in the end.