Boyfriend masturbated while I was there?? HELP?!

Hi, okay I'm having a problem. Just now my boyfriend confessed to me that he masturbated after he got home from work yesterday and I was home, he said he did it in the shower. To be honest it hurt my feelings a little bit because I'm a bit of a horn ball and am always trying to get him to have sex with me. It also hurt my feelings because I was RIGHT THERE and wasn't busy so I could t helped him out in that situation. He said he didn't mean to hurt me, but I don't know how to take it. Should I be upset?