My boyfriend and I have been dating a year. He's a very outgoing person and spends a lot of his time at work, at school, and with his friend Kristen. While I know he and his friend would never do anything, it immensely bothers me when they hang out- mainly because them hanging out includes dinners for two at nice restaurants and seeing plays and movies I've let him know I want to see. I find that, more and more often, he is cancelling on our plans because he is so tired or he opts to have a day indoors instead of us going out. This normally wouldn't bother me, but we haven't done a couples activity save for eating out in over a month. I never hear of him cancelling with his friend. I have no fear that he is cheating on me, but I still wish he would invest more activity time with me. I'm starting to feel a bit unimportant and lowly. If my self esteem were any lower, I would have to see a therapist.
So my question is: Should I say something to him about how I feel pushed-aside, or should I keep filling my time with hobbies and activities? If I do say something, how should I phrase it?