After great sex I tell my partner how wonderful she made me feel as I lay there calming down from my intense orgasm. It is usually my present partner that I think of while having sex. I concentrate on watching her and how she reacts to what I'm doing or I let her know how what she is doing affects me. Talking to my partner during sex keeps her in my thoughts. Staying in the moment my mind doesn't drift off to someone else. I don't have to tell "Julie" how great her pussy feels while I'm fucking "Kay" because my mind is on fucking "Kay", not "Julie". After it's over I let my partner at the time know I had a great time with her and how it felt. Now during role play I will tell whoever I'm playing with that I am fantasizing about "Julie" as I fuck her. But I say so before, not after. She might play along and let me know that it is "Tom" who is giving her great sex. Or she may take on the role of "Julie" and fuck me dry. That's what makes it all great sex.
Her most common statement after great sex is, I got off when I pictured you laying down with a Hispanic girl on your dick and one sitting on your mouth kissing each other. I tell her I imagined her with a look of contentment on her face while getting double penetrated by 2 huge black cocks. Then she says, "Those old memories."