Since it came up in discussion, I just had to look it up!
According to the Macquarie Dictionary Book of Slang
snog verb 1. to kiss and cuddle; canoodle. —noun 2. an act of kissing and cuddling: a quiet snog in the corner. Also, snoog. [origin uncertain; see obsolete snug to copulate, or cant snoodge, variant of snooze to sleep with a woman].
Chocoholic says I’m a good snogger! (“I am very fond of kissing you” is the direct quote.)
