Green’s Dictionary of Slang

corporal (love) n.

[pun on SE; it ‘stands to attention’]

(US) the penis.

[US]H.N. Cary Sl. of Venery I (t/s) n.p.: Corporal love the penis.
[US]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.