A submission recently used the phrase "pashing off"; from context, it was clearly Australian slang for something in the general vicinity of either kissing or making out. WordWeb Online says to pash is to "Kiss, embrace, or fondle with sexual passion"; Urban Dictionary says pashing is "heavy duty kissing between teenagers"; Free Dictionary says a pash is "a romantic infatuation" or "the object of such an infatuation," and that it's short for "passion." (That last pair of definitions sounds to me like it matches US use of "crush," which can be either the feeling you have or the person who you have that feeling about.)
Versatile word! I suppose you could say "I had such a pash for my pash that we started pashing."
'Pash' meaning 'passion' goes back a loooong way. 'Tender pash' is in the lyrics of "'S Wonderful," copyright 1957.
OTOH, that song is all about silly abbreviations. Maybe the lyricist actually invented the word 'pash'?