How do i get my bf to give me more then just a pec...guys help!?

im 14 and my bf is 15 and we have been going out for 2months and he has only gone as far as a peck on the lips, so how do i get him to go farther without telling him...is there any tips to show him im ready?or to keep him from backing away after just one kiss?guys how did you know and what makes you want to go further...