A kiss is just a kiss t-shirt

Remember that song, 'as time goes by' from Casablanca, or of course the slow paced 90's UK comedy (wait...that was a comedy?) aptly named "as time goes by" with Judi Dench in it?
Well now we've found the perfect combo, a song, maths references, physics all in a single t-shirt. All hail...

a kiss is just a kiss t shirt

a kiss equals a kiss,
a psy = a psy
the fundemental things apply (like Einsteins theory of relativity)
as t goes byyyyyyyy!

Whaaaa....?