If it was just on the outside, it's possible but highly unlikely. However, if you were having sex and using the withdrawal method, there's a higher risk of pregnancy because pre-cum contains a lot of sperm.

Tell ur boyfriend that he has to find smaller condoms...Lol.... Seriously. His mentality is messed up.. For all men that is.... I would kno, I am one. He thinks his thing is bigger than it really is. He probably usning wut im using, magnums. Tell him to seriously find smaller condoms, as the ones he is using arent tight enough around his penis. Best of luck.