If you come clean with your therapist, you'll make better progress. I don't understand why you aren't direct and honest with him. He's only there to help you. I don't think he's hitting on you nor do I think he's a louse for commenting on marriage compatibility. I also don't believe he knows anything about Sam other than what you've told him. If you haven't given him any reason to doubt you, why would he? Remember he thinks you're mature for your age. That's not an inappropriate comment, it's a compliment.