When a perky pop star pairs up with Hollywood's handsome devil du jour, don't count on candlelight and clever chat. Instead, on the morning of Jan. 28, Britney Spears, 21, was spotted in L.A. getting a manicure, wearing an odd sleeveless shirt and smoking a cigarette. She and her squeeze-of-the-moment, Irish actor Colin Farrell, 26, later caused a ruckus by appearing together at the premiere of his new movie, The Recruit. They ended up smooching on a hotel balcony, but Farrell insists that "we're just mates and we're not dating." And the Irish lad also insists he's no lady-killer: "I'm just a 26-year-old guy who's single and having a good time." Evidently, young man, evidently.

11 a.m.
Preparing for her night out, Spears, sporting a tank top bearing, in delicate, tasteful type, the words "F---You," heads to a West Hollywood nail salon. Later, she steps out for a smoke.

7:30 p.m.
The twosome set tongues wagging on the red carpet at the premiere of Farrell's flick The Recruit. (Curiously, the one displaying midriff is...Farrell?) She calls him "an amazing person."

Midnight
Spears, who ducked out of the Recruit screening early, and Farrell rendezvous at the Chateau Marmont hotel on Sunset Boulevard. She joins Farrell in his suite, where a party is in full swing. Among the guests at the do: Farrell's Irish family, including his brother Eamon Jr.

2 a.m.
The couple—growing more affectionate—share a private moment on his balcony. She heads home before sunup.

The morning after
Farrell cracks a beer on the hotel balcony with his mates; later, the tireless lad reads his new Playboy interview alongside an unidentified woman (not Britney).