The Root of the Problem
In his mind, the whole mess between Sienna and the Kensington family happened because of Lorelei. He felt that Sienna was jealous that everyone in the family loved Lorelei and ignored her. If she hated anyone, it was definitely Lorelei.
Worst case, he could just toss Lorelei to Sienna and let her deal with her however she wanted.
After all, Lorelei was just an adopted daughter. He'd given her a go