It sounds like it was just an offhand remark related to the movie you were watching. If you suffer from body dysmorphia then maybe that was the wrong movie for you to be watching together.
In subreddit r/relationship_advice
In a post titled:
My (F30) boyfriend of 3 years (M30) just said that if he had a Megan Fox bot he'd be banging her every night … what would your emotionally mature response be to that?