Most Helpful Guy
Well, you are perceptive and realistic. The only questions are: how valuable are you to him in other ways besides your looks/body? And how moral and loyal is he?
You're right that LA is full of hot women, and a lot of them quickly learn to use their sexuality to get what they want (often successfully, at least to a certain extent). No doubt hot women will come on to him - even throw themselves at him.
But if you are making him happy, not just sexually but emotionally and spiritually, then if he has decent morals, he isn't going to stray. If you DON'T make him feel that you are supportive, or are overly needy/clingy, etc., or if he doesn't have high moral character, then you're in trouble.
A woman doesn't have to be "perfect", especially not physically, in order for a man to be attracted to her and love her. If you're an 8.5, then a 9 or 9.5 isn't going to sway him if your personality and attitude are also great.
But we don't know him, or you, so you'll have to be as objective as you can and do your own evaluation. You may want to, you know, actually TALK about this with him too...