Albino Parakeet Question?

I've had an Albino Parakeet for about ten days, and I still don't know the . My other one has a purple cere, meaning it's a boy. My ablino has a white one. Now how do I tell?! They are caged together, and sometimes Nemo (Boy Parakeet,) sits on my white one's (Angel's,) back and flaps his wings. What does this mean?