are they official? like bf and bf? or what??

Not really.
This is one of those couples who gradually just get closer and closer without giving the relationship a name. With these couples it's the endgame to have them say they are in a relationship and they love each other. Kinda like Viewfinder and such.

Given the BL setting and them definitely being meant to get together tho, we can basically say yes. Tho I bet you there will be a dramatic arc in which they seperate and then make up and get together. That's the basic plotline of these kinda couple's dynamics. Like a rule of thumb, if you so will. XD