Spirit wings is correct. I have also seen pairs mate but not lay. It depends on the birds but usually if they have a proper nest site they will lay. Just remember two males will mate and two females will mate. For some reason they will play the role if there no other sexes available.
I agree with spirit wings. I have two gay pair right now and I just let them be. I just put some dummy eggs so that they can feel happy. They were probably almost a mate now for almost a year,but because I don't like both of them (both are bullies) and I can't cull, I just want to make sure that they stay as partners. Yeah, I am evil with a dirty plan.
Separate your current breeder and get some new birds that you actually know their sexes and force mate them with your current ones.
First figure out their sexes. Then if you find that they are of the same sex then find birds of the opposite sex and you'll have eggs before you know it. If they are of opposite sexes then they might not comfortable in the loft. Just somethings to think about.