My girlfriend dropped an earring down the drain. The P trap (or J bend, actually) should be easy to remove, but after twisting off the two nuts, the trap is still stuck to the pipe coming out of the wall. I guess the gunk that has accumulated over the years is gluing them together.

Any tips on how to separate them? Thank you!

Is the trap a pvc trap? The installer may have glued them. The gunk will not stop you from taking it apart. You may need to cut the trap and replace it. Use a catch pan so the cabinet does not get wet.

That had crossed my mind. But why would someone glue it AND still use the nuts? Some water did come out when I loosened the nut where the stuck joint is. I guess that still doesn't preclude glue, though, because twisting and knocking the thing doesn't make it budge.

Thanks for the suggestion. May have to just cut... :(

A glued p trap mostly never leaks and almost always garrantees the plumber will get the next service call because you are likely to not know what to do. Also he may have had trouble with it leaking and simply glued it to stop the leak.