Crystalan, I am sorry not to be positive, but he does not seem so in love with you...
First of all, for almost every man, having a bisexual girlfriend is simply a superlative thing. it stimulates men's fantasies, it makes them first of all proud but damned curious too. No serious guy would ever say to her girl: "Go and explore your sexuality alone". It's without question. A man in love would probably do everything he could to share that experience, not necessarily physically, but at least intellectually. And he would support his girl in the process.
If it's true what you are saying ("to go ahead and see what it's like with a woman without him"), I am sorry but I am afraid he does not care about you so much.
Few signs of this lack of commitment could be his way of communication: does he prefers to chat on internet or to send you text msgs rather than calling you?
Because it's much easier to do "something else" while chatting on the web or texting rather than talking at the phone..
You can even text several people at the same time, without showing any sign of "distraction"....
And if he calls you, does he usually end the phone call in a sudden way, maybe saying that he cannot talk any longer because he is busy? That is not a good sign too..
Maybe I am wrong. Maybe when you chat the webcam is always on and it's clear that he's focusing his attention only on you.
Moreover not showing up to a date can happen from time to time. And it's not normal. But if it happens pretty often, I would start to think that the valid reasons are probably just good excuses...
In addition I was in college too...I recall picks of overload, but if his busy period never ends....that's kind of sospicious.
In a relationship that really works, you should not fee insecure about your partner's love....never.
Probably I was too negative, but at least you can find in my posts some details to think about.
In any case, even if I am wrong, you should show more indipendence. It would surely help the relationship.
Take care!!!
And sorry for my English, I'm not mother tongue