What is Off-fuck?
1.
Similar to the wing man in action the purpose of the "off fucker" is to take the attention of the secondary target and allows the main target attention to be directed to the main fucker. Similar to the way an off tanked mob is dealt with in many online games.
After you and the your wingman get a couple of chicks back to your place the wingman will off-fuck the lesser of the two so that you can main fuck the good looking one.
See