Many people would agree

That part of lustful fantasy

Are hormones of a loving sort.

Therefore, before a lustful thought

Occurs, one must have understood

The fact of loving: bad or good,

And so, to carnally succeed,

A wizard or a witch might need

To prior penetration know

What lust or loving is, and so

To put it in conciser terms

This soliloquy just confirms

What's been deduced through circumspection.

Riddle can't get an erection.

...

A/N. Maybe a bit of a stretch of the imagination, but, if you're incapable of loving anyone, how are you going to ever get a hard-on? ('Fraid it's not the best poetry, this time.)

Alibi