The act of putting on your sweater to reduce the risk of getting close to the gernade
When a fellow bro is about to take a gernade for another bro and might need some extra protection. So he throws on his sweater to reduce the damage taken.
John: dude look at that eye candy over there
Dave: man thats one narley gernade shes with
John: Bro i want her,.. you have got to help me out
Dave: god damm it, alright. give me a sec. gotta throw my flak jacket on