Green’s Dictionary of Slang

corporal (love) n.

(US) the penis.

1916		H.N. Cary Sl. of Venery I (t/s) n.p.: Corporal love the penis.
1974		J. Lahr Hot to Trot 209: They’ve got a knife in one hand and their ‘corporal’ in the other. They push you on the bed.