Look, their lives are exciting enough. When they have some downtime, maybe they like to spend it by playing pretend that they're a perfectly average suburban couple with 2.5 kids, a dog, and a mortgage. They make up ridiculous work stories about non existent annoying coworkers and all the tiny details of their imaginary normal jobs, they talk about needing to fix that leaky pipe, they pick a movie to watch after dinner.

Sometimes it's sexual (dirty talk about doing the laundry), sometimes it's comfort (they might not actually get sick, but it's kind of fun to pretend that Nicky has a cold and Joe has to take care of him), sometimes it's a little of both, but it's nice to take a break sometimes.