Ashton Kutcher and Mila Kunis are apparently happy just to take their relationship slowly.

The former That 70s Show co-stars have gotten closer following Ashton's split from Demi Moore last year.

And although they have not formally announced they are dating each other, they have been seen spending lots of time together lately.

But Us Weekly reports that the Hollywood twosome don't feel a need to define their relationship and are happy just to take it one day at a time.

"They're not exclusive, but they are hanging out and seeing where it's going," a source told the publication.

"They've been hot for each other for years. It stretches back to when they were friends on the show."

Ashton's six-year marriage to Demi ended after he allegedly cheated on her on their anniversary although they have yet to file for divorce.

Meanwhile, the Black Swan actress was in a long term relationship with Home Alone star Macaulay Culkin which ended last year after eight years together.