LOS ANGELES (AP) A stakeout leads to a smooch on ABC’s crime drama “Castle,” with Rick Castle and Kate Beckett finally sharing their first kiss.

Played by series stars Nathan Fillion and Stana Katic, the pair locked lips in a scene filmed outside a downtown warehouse late Thursday for a January episode.

As “Castle” fans know, the show’s weekly whodunits share equal weight with the will-they-or-won’t-they romance conundrum for the lead characters.

Castle is a best-selling mystery writer and single dad who is an eager consultant with the New York Police Department. Beckett is the no-nonsense detective ordered to work with him. Their growing sexual tension and banter is reminiscent of the 1980s “Moonlighting” mystery series with Sybil Shepherd and Bruce Willis.

Sooner or later, however, TV viewers demand results from such chemistry lessons.

“Castle” executive producer-creator Andrew W. Marlowe said on Friday he’s aware that many loyalists are rooting for Castle and Beckett to “take their relationship to the next level.” The show couldn’t hold off forever, Marlowe said.