Oh, that is too bad that it did not work out for you. Has this pair ever had any chicks before?
I have a pair of parakeets myself and I have never witnessed them mating. I do not think the hen wants to be seen doing it. Every time the male is clearly in the mood but there are people in the room she first ignores him, then pushes him away if he persists. I think they have done it at some point thought because he is not at all as desperate as he was at first. I don't know if the hen will ever lay an egg though. I have never given them any nesting materials or box to make a nest if they did, so I don't think any egg that might come would be able to survive.
Good luck next time, I hope you can get some chicks.