"I haven't [been in one myself], but I can give you my stance on it: It's like communism -- good in theory, in execution it fails. Friends of mine have done it, and it never ends well," Kunis tells GQ's August issue. "Why do people put themselves through that torture?"
The actress, who poses in numerous states of undress, adds that it's nearly impossible to maintain a sexual relationship without developing an emotional attachment.
"Friends with benefits isn't a purely sexual relationship -- it's two people who like each other having sex, not a random hookup. And when two people who like each other have sex, eventually someone catches feelings and everything is f*cked," Kunis says. "You might be able to treat our relationship as killing time. I might not. I may be in love with you."
The Golden Globe nominee, who split with Macaulay Culkin in January, is currently single -- and happily so. "I wouldn't dare wish myself upon anybody at this point in my life!" Kunis laughs. "My shooting schedule is crazy. I'm a nomad till January."