Rock 'n' roll offspring Sean Lennon and Elizabeth Jagger have sparked rumours their romance is back on after spending the evening together in a London hotel. The children of rock legends John Lennon and MICK JAGGER started their night in private members' bar AvivA, but were eager to escape to private quarters. The couple enjoyed a year-long relationship two years ago (04). A source says, "They arrived together quite early in the evening when the place wasn't so full and sat a table where they wouldn't really be noticed. They were chatting and laughing. There was a definite spark between them. Lizzie looked stunning and Sean couldn't keep his eyes off her. "There was lots of flirting. They kept touching hands and snuggling up against each other. But they didn't stay in the bar long and disappeared upstairs. No one saw head nor tail of them for the rest of the night."