The birthday plan failed but there was something that William came to learn. The Siren family is obviously in his favor. They wanted him to marry Elisha, rather than Magnus. They would do anything as long as it wouldn't cross the line or be traced back to them.
This is like having a boost that can help him in the quest of getting Elisha.
Even if she loves him, without canceling the marriage contract, he can't get her. The Siren family was the one who actually initiated this contract and if they initiated to cancel it, then they have to pay a lot of compensation and it would degrade their status in the noble circle.
If the Rutgurd family was at least a duke family, then there would be no one who would make things problematic for them but the Rutgurd family is only a Count family. So there would be many who would make fun of the Siren family.
