As an extension of regular 'pashing', Canadian pashing refers to the act of sticking ones fingers down the pants of another person during regular pashing, with the intent to sexually arouse and excite the other party. The term 'Canadian' is added to downplay this act as 'Canadians are too nice to do this'.
Perakn1: "Oh man, I pashed
this bird hard last night at the club!"
Peraon2: "but have you given her a Canadian pashing yet??"