I knew my first boyfriend through the net for years before we really started hanging out together in our chatrooms. Then we introduced webcams -- good indicator of body language -- and it wasn't as if we hadn't seen each other before. We exchanged pictures and all of that jazz when we were friends. So then we said we were exclusive.
So then we introduced the MSN talk feature..and then we talked via telephone...and then we met in real life...and then we had a relationship for a year and change.
So absolutely, yes, you can have a relationship via the net. And you can declare yourselves boyfriend/girlfriend -- that's commitment, meaning you're not going to go shag other people.
As to comments that "internet relationships and friends aren't real," pft. My most constant companions and consistent friends have been on the internet.
"Oh tell me where your freedom lies
The streets are fields that never die
Deliver me from reasons why
You'd rather cry; I'd rather fly." -- Jim Morrison, The Crystal Ship
"The future ain't what it used to be." Jim Morrison.