From your description of what you're trying to accomplish I think what you need is an adapter that is 2 female, 1 male, like the one Ericjcabrera offered.
An alternative to a cable Y adapter is this kind of splitter. It gives you a direct connection and is probably less expensive than the high-quality cable splitters. I've used this Audioquest version in a couple of setups and it works perfectly. Monster makes a high-quality one, as well.
An alternative to a cable Y adapter is this kind of splitter. It gives you a direct connection and is probably less expensive than the high-quality cable splitters. I've used this Audioquest version in a couple of setups and it works perfectly. Monster makes a high-quality one, as well.