If Lucas were to walk in at the wrong time (such as when Sidwell shot Dr. Dogkiller) Lucas would be dead. If Pascal were to witness Lucas overhearing another secret, Pascal would kill him.
Marcus has two choices -- he and Lucas can get their own place and he can WORK at Wyndemere and then come home or Marcus. Or have the two of them live apart until after Marcus is ready to leave Wyndemere. Lucas also has responsibility here and if he wants to wait things out with Marcus, he should move out and have the two of them date and Marcus can sleep over.
What Lucas unintentionally overheard put his life in danger so Marcus can no longer pretend he an keep Lucas safe at Wyndemere while his father works there.
Karen L.