Shawty is actually in prevent
Cause the one in front is working deep threat, yep

from Wale (Ft. Tiara Thomas) – Bad Lyrics 4 on Rap Genius

Wale uses a football reference here as he has been know to do in many of his songs (here for example). Shawty is in “prevent” (i.e. shunning advancements) or in defense mode because the guy courting her currently is aiming for a long term relationship (deep threat).

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