Is this wrong or not?

[Fifi]

My boyfriend is currently following a porn account on twitter, which tweets pictures of beautiful girls performing sex acts or being nude. It's kinda made me feel a bit crap about myself, seeing as I'm only 15 and I want to wait until I'm ready for sex. My boyfriend insists he's ready to wait, and I've kept him waiting for 5 months, but I know he's getting impatient, because we had a bit of an argument about it last night, but he apologised after. I don't know whether I'm over reacting by him following these accounts, but it's making me feel so worthless and angry inside, and I don't want to have another argument or risk losing him :/ do you think I'm over reacting, or is it wrong of him to do that (I even told him last week I don't like the idea of him watching porn, but he says it relieves him of being horny so...) ?