Just when it seems like the GOP presidential primary couldn’t possibly sink even lower into the mud, Florida senator Marco Rubio has proven he’s up to the challenge. During a campaign appearance in Virginia, the candidate insinuated that opponent Donald Trump has a small penis.

Trump’s digits have been dubbed “shrimp fingers” by Washington Free Beacon blogger Andrew Stiles, but the observation isn’t new. Desparate for a way to insult Trump, Rubio has reached for gossip and innuendo.

After Trump called his opponent “Little Marco Rubio” on Twitter yesterday, Rubio fired back during his rally after acknowledging that Trump is taller than he is. Rubio pointed out Trump’s unusually short fingers and then followed it up with a sharp jab below the belt.

“And you know what they say about guys with small hands,” the senator said.

As the crowd laughed uneasily, Rubio delivered his punchline. “You can’t trust ’em!”

Rubio also took aim at Trump’s notorious orange complexion, saying Trump “doesn’t sweat because his pores are clogged from the spray tan. Donald Trump isn’t gonna make America great, he’s gonna make America orange.”