Slow it down, Miss Nicky.
If he is groping you without your permission just 14 days after you started seeing each other, he's going to go as fast as he can get away with. Slow that boy down now before his hormones get the best of his better judgment.
You only just hit your teenage years, and though it is my stance that when a person is ready to be physical that they will know it, you are different, here is why:
Girls with eating disorders are at a 40%+ increased chance of becoming rape victims. The reason being that rape is not about the sex, rape is about power, and most rapists have insecurities about being in control. Young ladies with eating disorders tend to be already emotionally compromised, and are viewed as weak, easy marks; they already have one problem they don't want to talk about, if they become even more recusive, hardly anyone will notice.
So Miss Nicky, you have to be very careful. You are at increased risk of attracting sexually aggressive types, as is already evidenced by your boyfriend stealing first base, as it were. Make sure he understands not to grope you uninvited anymore, or you will stop being alone with him. It is for your own safety.
Since you are very young, please take this link and keep this important information for your personal reference: http://www.newhopeforwomen.org/abuser-tricks
After some time has passed, if your boyfriend has cooled his Roman hands an Russian fingers, as it were, then if you feel ready to become physical, it becomes at your own discretion. But I reiterate, see if this boy can control himself first. At your age, it is paramount to slow your actions down so your mind can catch up. Teenage years are notorious for poor impulse control and lack of forethought. Be one of the exceptional teens who thinks ahead rationally.
You are among friends here, Miss Nicky. If you ever need to talk, my inbox is always open.