Niles has it all planned out, he wants to make everything perfect when he pops the question to Daphne, the only problem is her mother, so Niles asks his dad if he would take Mrs. Moon out, and Martin agrees, though he is really drunk.
So with Mrs. Moon out with Martin Niles has Frasier to help him with everything, but everything changes when Daphne shows up with the flu, so Niles postpones everything, and Frasier tries to get everybody out of the house without Daphne seeing.
Though the setting is just right and Niles pops the question to which Daphne accepts.
I loved the part after Daphne accepts Niles proposal someone comes from the stairs and as they are about to play Frasier jumps them, very funny, I wasn't expecting that.