Going in raw...

Katie
So I'm on the implant form of birth control, Implanon. My boyfriend and I are very sexually active and he NEVER wears a condom anymore. I'm not worried about any STD's, but I am worried about the fact that he cums inside of me. 
I have not gotten pregnant, as the Implanon is very effective, but is it bad that he is almost always finishing inside of me? Should I make him finish elsewhere more often, or better yet start using condoms again? 
PLEASE any help is appreciated!!!