Nope, still stuck. A couple more hints, please
18a Lying bums hide beneath their disguise (5,7)
F?L?E,?*?T?M?
4d Meddling kids initially snoop, eh? Most plausible (6-6)
S?O?T?-S?*?E?
(The * is the letter in common)
I can guess the first word in 18, but a second doesn't spring to mind!