The Spy Kids actress shared the good news via Instagram, posting a photo of Pena with the caption "Hello fiancé."
Pena popped the question to Vega, who's been married once before, during a recent road trip. On Wednesday, he posted a photo of Vega sporting her massive engagement ring. "My angel!!! @vegaalexa awesome road trip so far!! Now we just need to get back," the Big Time Rush singer wrote.