Meg Ryan - Ryan And Mellencamp Dating?

Sources claim the When Harry Met Sally star, 49, enjoyed a recent coffee date with Mellencamp, 59, in Martha's Vineyard, an island off the coast of Cape Cod, while the stars were seen food shopping together in the Big Apple earlier this week (begs03Jan11).

And they were reportedly so loved up, they had onlookers convinced they were an item.

An eyewitness tells People.com, "She (Ryan) usually comes in by herself or with her daughter. I thought that was her husband because they seemed comfortable and familiar with each other, just like an old married couple."

The news comes less than a week after Mellencamp's spokesperson announced the veteran singer/songwriter had split from his wife of 18 years, supermodel Elaine - but insiders claim the couple had already parted ways when the rocker reportedly first stepped out with Ryan in November (10).

Ryan, the ex-wife of actor Dennis Quaid, was last romantically linked to Susan Sarandon's former partner Tim Robbins, although a representative for the actress shot down the claims, insisting they are just "great friends".

She is mother to 18-year-old son Jack, from her union with Quaid, and six-year-old daughter Daisy, who she adopted from China in 2006.