Man, I love this picture and I don't even know who these two are.
Looks like the short one in the front has just reminded the taller one of a time in the recent past when they had absolutely mind-blowing, life-changing sex. Like, the short one did things to the tall one that have haunted the tall one's dreams ever since. The tall one can't have a sexual fantasy now that doesn't involve that night of passion. And the short one just now said "Hey, remember that night when I...."