Gullible

Kaven brushed off his thoughts seeing Arihan in a terrible mood and focused on what was important.

"We can't accuse a prince recklessly." Kaven was also doubting Agost but speaking without a single proof wasn't going to end well even if the royal family trusts them. 

The royal family would be answerable to Crisal and they would be helpless against Agost.

They wanted to keep an eye on Agost but, "We can't leave a spy in the palace. So Dad will speak with the Crown Princess to monitor Prince Agost." 

They weren't doing it all because Alora was in danger in their home. Darwins were always loyal to the throne. It was their duty even if Alora hadn't gotten close to them.

Kaven came to the important point of why he was waiting for Arihan, "We want you to be around Alora." It wasn't his decision, James had the same thoughts.