She hasn't, from a certain point of view

"Technically, I haven't?" Samantha said defensively.

"Technically? So substantively you cheated?"

Samantha waved her hand. "You know how you imagine m... I mean, you imagine being with an actress or someone, and doing the deed with her? So since you're not really doing it with her, it's not cheating?"

"Ah, like I'm doing it with you in my imagination while masturbating?"

"Yea... that,"

"Wow, I never considered the fact that I substantively cheated with you," you say as you rubbed your chin thoughtfully. "So with whom?"