Thanks for responding, Michael!
There are a couple of issues with your suggestion.
First of all, while Peeper's OTHER advances are met with a violent reaction, Vivi allows him to preen the top of her head and sometimes feed her. I think this is because she's barely a year old and sees it as parental behavior. But Peeper takes this as encouragement. It's prevented Vivi's rejections from having any impact. I am worried that when she gets older, things may get more violent because she unknowingly encouraged him in the past.
Second is the sheer fact that Peeper hates people. I've had him far longer than Vivi and did manage, at one point, to recall train him. But I can only get him to do anything at all for me if I hide his cage, hide his food for a full day (he won't do a thing unless he's half starved, hence I no longer bother. I think it's mean.) and put him in a partial wing clip. That's not to say he isn't tame. He's never bitten anyone and steps up just fine. But good luck getting him to stay there. I do know what I'm doing, and I've had wonderful, people-oriented budgies in the past. And if I recall Vivi in front of him, he either lands on my hand immediately after her and chases her away from the millet, or lands on her back, which is NOT ok with Vivi. Fighting ensues.
Peeper has never been interested in people at all. I spent the better part of three years focusing my full attention on him, but despite getting some basic commands down he would always, even if all his toys were taken away, choose to socialize with his food bowl rather than give me the time of day.
I had been rushed into buying him by my mother; 'If you're getting a bird, you pick one from this store, and in the next five minutes"
I strongly believe Peeper would be much happier in a different home with other budgies, but my mother refuses to let me try to re-home him. She says it would be cruel. What I think is cruel is forcing him to stay here when he'd be far, far happier in an aviary.
Sorry for the rant.
Yeah, waiting for Peeper to take a hint isn't going to work. Vivi sends mixed messages, see.