approach condoms to bf

So, my bf and I have been going out for almost 3 months. We have been doing some foreplay things.... when we were hanging out he kept rubbing he penis near my vagina. I told my mom and best friend about because I was worried that I could get pregnant because there is still a chance of it happening even if it dosen't go in. I'm planning on getting birth control, my mom is setting up the appt. But I bought condoms to be safe... how do I approach to him that I want him to use a condom while we are doing "stuff" just to play it safe?!?!