The glamour model met up with the actor for talks at a west London hotel on Monday, where they are rumoured to have spent the night together.
Kelly, 28, announced she?d called off her engagement to Billy, 42, last month after 4 years together.
But the Titanic star flew in from a film set in South Africa this week to try to win her back.
?Kelly was giggling and looked very happy,? an onlooker at the hotel tells The Sun. ?She kept touching his arm.
'Billy looked like the cat that got the cream. But she seemed to be teasing - it looked like she was keeping him on his toes.?
Yesterday, the couple visited Kelly's £1million Kent farmhouse - but the
Strictly Come Dancing star still wasn?t wearing her £35,000 engagement ring.