You could talk to him about unprotected sex...but you just have to know what's at risk. Everyone can tell you all day that unprotected sex is TERRIBLE and you'll get STDs (OMG) and blah blah blah, but honestly, if you're on the Pill, you don't miss any, and he pulls out when he should, you've got a very looow chance of pregnancy. Communication is key here, so talk to him about what you want to do. If he wants to wear a condom, respect that.
If that turns out to be the case, do your homework. You can visit Trojan and Durex websites to see what they have to offer. I know Trojan has Magnums for the larger guys, but I'm not sure what Durex offers. Just try some new things out until you find something that works for the both of you. =]