"I love you. Here's a giant, hissing cockroach."

The Madagascar hissing cockroach is huge. And it hisses. How romantic! You could even write a love poem about it:

The way your cockroach hisses

Is by forcing air through the breathing holes in its thorax

This is sort of like the way

That I love you.

Not bad! And if you want to get REALLY lovey-dovey on Valentine's Day, go by the Bronx Zoo's website. You can name a hissing cockroach for the one you love! (The Bronx Zoo motto: "Flowers wilt. Chocolates melt. Roaches are forever.")