The way you feel about your body is a very personal thing, so for you, what he said to you was very hurtful. For others, it may not be as hurtful and it's easier for them to brush off a remark like that. You are not wrong for feeling the way you do, a lot of people would be hurt by that. However, in the context of your situation, you two were playing around and it sounds like he took things too far, but he didn't actually intend to hurt you. I think this is the kind of thing that will just take time for you to get past. How remorseful did he seem when you brought it up to him? Did he seem sincerely apologetic and unaware of how hurtful his remark to you was? Did he reassure you that you are beautiful and that he loves you and your body? I think that as much as his comment stings, that you should look to the positive actions he is showing you. Everyone says and does things that hurt other people, sometimes. It's not because they actually want to hurt you (although some people are like that, but they are actual a$$holes), but they are unaware that a line has been crossed. I think now that you brought this up to him and he felt bad about it, that he won't ever make a remark like that again. Hopefully not anyway.
"Caring is not an advantage."