In Spike Jonze’s movie Her, an artificial intelligence operating system (voiced by Scarlett Johansson) comes up with a somewhat perplexing idea in order to have real, embodied, sex with her lover, Theodore. She recruits a woman to act as her surrogate and “become” her body during sex. Theodore tries to follow through with the plan, but after a few minutes of kissing Isabella—the human facilitating their carnal relationship—he cuts the experiment short, deeming it “too strange.”

The era of human/robot love may not be upon us yet, but people and smart devices are already engaging in this kind of three-way: Two humans in a long-distance relationship (be it friendly or more) can touch, or be intimate, through technology. Remote hugging machines, for instance, make it possible...