(Most of my faves are from Pynchon's "Rocket Limericks," which I have tapes of myself singing ... They're about Allied troops who encounter a German V2 site and (variously) fall in love, or at least lust.)

There once was a fellow named Ritter
who slept with a guidance transmitter
It shriveled his cock
which fell off in his sock
and made him exceedingly bitter