Is it okay to tell my partner I'm scared for him?

My partner has confided in me about his urges to go deeper, and I was just wondering if it would be okay to say that I was scared for him. He tells me he wants me to be honest with him, and I just want him to see how concerning it is, not from a point of disgust but from a point of love and care, as he says he cant seem to see how concerning it is. Would this be okay?