Ashton Kutcher prefers to declare his love for Demi Moore online.

The 32-year-old actor - who wed the 48-year-old actress in September 2005 -thinks using social networking websites to send affectionate messages to his spouse is no different to sending flowers to the workplace.

He said: "Sending sweet nothings on twitter or Facebook is fun. In some ways, it's no different than sending flowers to the office: You are declaring your love for everyone to see. Who doesn't like to be publicly adored?"

However Ashton - who is renowned for his love of social media and has admitted to tweeting his wife even when she is sitting beside him- has warned people to be careful of what they post online.

He wrote in an essay for America's Harper's Bazaar magazine: "Just remember that what you post is out there and there's some stuff you can't unsee."

Although Ashton loves to declare his affection for wife Demi online, he does admit a computer is no substitute for human contact.

He said: "When someone needs us, he or she needs all of us. There's no text that can replace a loving touch when someone we love is hurting."