Ashton Kutcher thinks one night stands are ''gross''.

The 36-year-old actor - who reportedly got engaged to his former 'That '70s Show' co-star Mila Kunis - thinks it's ''fun'' being single for a while but grew tired of his no-strings attached encounters.

The 'What Happens In Vegas' star told Men's Fitness magazine: ''Being a single guy can be a lot of fun ... when you're financially independent [and] can do whatever you want, whenever you want....

''For every girl you have a good time with for one night, if you want to stay single, that's the same girl that you have to not call back.

''After a while, being the one night stand guy is also just a little gross.''

Ashton - who was previously married to 51-year-old 'Ghost' actress Demi Moore - will soon be reunited on screen with his former co-star Mila as she is set to appear alongside him in the hit CBS series 'Two and a Half Men'.

The network announced this week the 30-year-old actress will play a young, free-spirited traveller named Vivian, who becomes Ashton's character, Walden's, new love interest.