Words our daddy taught us

It's getting late, and Phoebe is starting to become grumpy: "I don't want to go to bed, and you're a blad yacht."
A blad yacht? Hmmm. What could she mean? It's obviously meant to be insulting, because she is really very annoyed. I decide to find out. "What am I darling?" I tentatively enquire.
"You're a BLAD YACHT!" (Louder and crosser, now, at my failure to understand her.) Why do I do this? I knew this would happen. I should have just agreed with her and coaxed her into her pyjamas. And of course, although this is now the point where I should really leave well enough alone and just agree with her, I can't help myself. I really want to know what this blad yacht thing is. So, on we go.
"A ...?" I leave a space for her to insert the phrase again.
"BLAD YACHT!!!"
Riiiight. I'm none the wiser here, and Phoebe is becoming puce. It's time to change my approach. "Say it more slowly my love, and then I'll be able to understand you."
She stops shaking her fists, and, only just able to suppress her fury, slowly enunciates: "You. are. a. bloody. idiot! BLAD YACHT!!!"
Ah, yes, of course. Now I see. I decide to concede the point: "You're probably right, my darling." I pause "But it's still time for you to go to bed. Nighty-night!"
"BLAD YACHT!!!"