A shag, only used by the same cutesy people in the same sense as their version of 'hug,' which is "huggle."
Basically they say a word and end it with 'le' to make it cute.
ROHAN: "Hi lisa"
LISA: "How r yooooo"
ROHAN: "Fine thanks, and you?"
LISA: "yaysies, i'm superr!"
ROHAN: "How's your boyfriend?"
LISA: "hee hee we had huggles n shaggles last nightttt!!! :D"
ROHAN: "Ok, I'm serious now lisa, are you retarded?"