My boyfriends cell phone?

My boyfriend never had a problem with me using his cell phone until today.... I was using the internet browser and came across something unpleasant. The internet browser was on a delay and I kept refreshing. When I came across the unpleasant link, I automatically made an assumption, and questioned him about it. I didn't see a problem with my delivery of the questionable link, but my after a few minutes my boyfriend got offended after he already answered my question. He has now decided that he is not going to let me use his phone anymore and that no other girlfriend has ever used his phone, or had access to everything. I am not saying he has anything to hide, but why all of a sudden can I no longer use his phone. I wasn't snooping around, I was looking for something on the internet. I know this may not be a big deal, but its just the fact of not being able to use his phone anymore, after I apologized for my questioning him is what's bothering me. He now says he cannot "trust" me with his phone.