I think my boyfriend's penis is getting big

Yes its normal...how old is yur boyfriend ?? and how much big do u mean....

Don't make too frequent like more than once a day and passing hours. I suggest not more than twice  week...If it makes urination harder it may become a really serious problem. SEE DOCTOR. If you mean by "becoming bigger" like swelling up and red, its an urgent EMERGENCY case. In anyways, it's not normal and leave the penis alone for a time, both of you!|-O

I say one week, you will say two-three days.. :-|

Dear girl why are you telling somehitng you dont know. She already knows what becoming bigger while erection. She means sometihng else by "becoming bigger". it's not any normal. Why would she ask if it was not odd. If this is told by the boy, that he has problems about peeing after few hours of erection, there is a problem. If there is no peeing problem, there is not much problem or there is no urgency. But tell him to leave his penis at peace for afew days, this is my suggestion as a precaution.

I have found an article tittled "Penis Tears After Sex". Google it you will find easily.There was a symptom of enlarging penis diameter unusually in a very short time or just during a sex......... I recommend him see a physican, Encourage him explains everything he knows about his genital.And dont listen to people. You know what to do. Dont liten to people especially who are too "relaxing"................ Dear women, or probably just girls! Have you ever had a penis? So why do you talk about? Did you ever see men talking about your breasts, Vaginal issues? You are not being helpful. You are likely being harmful, misdirecting!