I don't know why combining characters oddly is fun, but I do love it. (Lex/Martha is another pairing I really kind of love, even though I only know of about 3 stories that feature it). But Lionel/Jonathan is actually a classic enemy slash pairing, and I think if more SV fen were interested in the older generation (Lionel, Jonathan, Martha) it might pop up more often.

Hey, you should post those stories! I'd like to read them.