Go to Victoria's Secret. They will measure you and find you the perfect bra that will be super comfy and make your breasts look amazing!
You can't without them telling you. His behavior is not going to give you the answer. It might be a hint, but you can't be positive. A guy doesnt have to be a virgin to be nervous, and lots of guys will cuddle and tell you "I love you" afterwards.
Thats hard to answer when we don't have an idea of what youre coming back at...