Look at how he instinctivly grabs her around the waist and pulls her in as she wanders away. Her huge smile and giggle as he does. He holds her by the hips and she moves her hand to massage his chest, and then gives him a kiss on the cheek. This isn't acting. Neither of them are good actors enough to play this convincingly. Then you add in all the random comments both of them have made in interviews about having personal secrets, or that neither of them would ever do a storyline like this without the other one. Liv even said that none of Dom's "side bitches" will take him from her. They're trying to see how far they can push it before Dom's wife calls and says she's uncomfortable. They're literally getting off on flaunting their affair under the guise of kayfabe.