What should i think? what do i do?

Me and my boyfriend have been together for almost 2 months. We spent all but 4 days together for the past two weeks (2 days one week and 2 days the next apart). Things seemed good. Well over the weekend when I was with him, he was on the phone with his mom and he told her I was there. She said something along the lines of "I thought you were tired of looking at her?" Not sure if the wording is exactly right, but something like that. He told her no. Of course he was really sweet after, but he before that also, so I was completely shocked b/c he definitely wasn't acting different. I didn't let it get to me too much because we were spending so much time together he probably just needed a breather an/or was in a bad mood when he was talking to her when he supposedly said it. So that was Thurs and I left on Sunday. We had been with friends and running around the whole weekend and by the time I left he was kinda grumpy and saying he needed to stay home and take a break then he made a