Okay, but what if there was a story where
one of them had anterograde amnesia, and 
couldn't remember the fun memories they were
making together because of that condition?
If it was Phil he'd know who Dan is, because
he had known him for a while before whatever
gave him amnesia, but he wouldn't remember 
if they kissed or anything. Or even if Dan admitted
that he liked him? (What a fail safe.)