Guys, what is my boyfriend thinking?

All last week we had plans to hang out, and then he would make silly excuses for all of them, and just go to his friend's house and get high or jam. I am really chill about things, so I shrugged it off and figured we'd see each other soon enough. Well plans fell through, but two days later I saw him at school for graduation, he kissed me in front of everyone and I asked him what his plans were for the day. He told me he was hanging out with his (guy) friend once again, I kinda just shrugged it off and went home. Later he texted me telling me he forgot to say goodbye. I asked what he was talking about, and then he explained how he was going for a school trip for a week (I know he actually is going, he is obliged to go) and that he can't bring his phone so we won't talk for 5 days. I told him I wanted to see him before he left and he said he had too much studying. I got pissed and told him how i was feeling... he apologized and made these plans for when he gets back. I haven't been able to talk to him in three days, but a girl told my friend she thought it was weird we're together because apparently he tells everyone he still loves his ex. Him and his ex are friends...HE broke up with HER. She doesn't have feelings for him anymore I know for sure and they haven't talked in a while. He's even showed his affection for me in front of her. I can't confront him about this until he comes home. Some of our future plans include hanging out with his ex and her boyish friend. I snuck a peak on his facebook before and he doesn't talk to other girls, and told her he doesn;t care if she likes other guys. What is his issue? Oh and I know for a fact he isn't cheating on me