They may be married to other people, but that didn't stop Katharine McPhee allegedly kissing former Smash director Michael Morris in broad daylight.

TMZ has reported that the pair are dating after they were pictured locking lips in Los Angeles at the weekend.

The stars, who first met on the NBC show which was cancelled in May, have both been married to long-term partners for several years.

Separated? Katharine McPhee and husband Nick Cokas in happier times

The Brothers & Sisters director has been married to actress Mary McCormack for more than a decade, and the couple have three young daughters together, aged between two and nine.

While the 29-year-old singer has been married to 47-year-old Nick Cokas since 2008.

The couple met three years before when they performed together in a stage production of The Ghost and Mrs. Muir.

However sources close to the couple told the website that the two have been 'separated for six months and are currently living apart.'

Married: Michael Morris and Mary McCormack have three young daughters together

It is unclear how Michael's relationship with Mary stands but it doesn't seem to be going well if these recent reports are anything to go by.

According to the gossip site, Katharine and Michael were also spotted holding hands and cuddling while strolling around Hollywood together.

The American Idol runner-up played Karen Cartwright in the musical show between 2012 and this year, in which Michael directed a number of episodes.

Smash: Katharine starred in the show alongside Debra Messing, Jack Davenport, Christian Borle, Megan Hilty, Jeremy Jordan and Anjelica Huston