Masturbating to images/thoughts of yr partner - c or d

I never thought the thinking about other people during sex stuff was real until the end of a relationship where I wasn't into it emotionally - during sex it wasn't that I was picturing another person or face, but there was just a mental block at seeing my partner as my partner. I had kind of disassociated from what was physically happening. As a friend who was exiting a relationship recently put things, it wasn't that Ryan Gosling was fucking her, just a faceless person who wasn't her boyfriend.

I don't think I've ever masturbated to images/thoughts of a partner specifically, but toward the end of the act it usually becomes about a specific sex memory for me, whether that's with a current or former partner.