Don DeAngelo had called him that morning after he had forbidden him to attend the party that night. He looked like he didn't feel comfortable talking to him but Donna was with him. It was obvious Donna asked Don to talk to him.
Don DeAngelo apologized to him, in his own way; he tried to. He asked him to attend the party to have an eye on her. Don told him that he told Marcella not to attend the party because she was underage and he had all sorts of people attending it, and it might not be safe for her. Don rightly predicted though that she will not listen to him and will attend the party.
That's all Don said. Donna had to add that he can clear the misunderstanding caused during the prom. She was very worried for Marcella as she had lost her "light".
