(Posted in 2 parts):
An aerial splitter is the obvious solution but, without knowing exactly how your aerial cable is routed, it's difficult to suggest precisely how you should go about it. The easiest place to introduce the splitter, obviously, is at the point where your aerial feed arrives into your living room (assuming that's where your main TV is). Simply plug in the splitter unit (probably about a quid or so from Maplin or even Woolworths) and you've got two feeds off one aerial. Yes, you do get a slightly lower signal strength off each feed but it's usually of no significance. (It's easy to think that you'll only get a half-strength signal off each feed but the science doesn't work like this. I've never had a problem using splitter units).
Now comes the tricky bit. You've got two aerial feeds but both are in your living room and one of the TV's to be connected to one of the feeds is in a bedroom. This is still not a great problem - at least in theory. All you need is the right length of coaxial cable (with suitable plugs at either end) linking your feed to the TV. Now, where you're going to put this depends upon the layout of your house, how good you are at DIY and how bothered you are about having cables showing!
I've got a coax cable, providing an aerial feed, permanently hanging down alongside my open-plan stairs but I live alone and haven't got to deal with the pressures of, say, a houseproud wife! It's more likely that you'll need to run a cable along an external wall (which is where the DIY skills come in!).