Graft Gaff Shag
The typical Scottish lad lifestyle of getting into other girls, where;

1. Graft her on Snapchat, Messenger, etc.
2. Plan or arrange to meet at a Gaff (house party)
3. Shag (have sex) with the girl in a bedroom of the same party (or similar)

It is then customary to follow the Pump and Dump scheme to then repeat the process with a different girl.
"John you planning on getting stuck into Susan tonight?"
"Aye, doing the old Graft Gaff Shag with her"