Actor Alec Baldwin has popped the question to his girlfriend, a yoga instructor who is 26 years his junior.The 30 Rock star has been dating 28-year-old Hilaria Thomas for about a year."Yes, it's true!" Baldwin's spokesperson told Us Weekly ."Alec proposed to Hilaria this weekend and we're all excited for the newly-engaged couple. Alec's birthday is tomorrow. Great way to celebrate!" Baldwin turns 54 this week. The couple both thanked well-wishers on Twitter, while Baldwin's daughter Ireland tweeted : "Congratulations to @AlecBaldwin an @hilariathomas on getting engaged! Love you guys. "I'm going to be a flower girl." Thomas was recently photographed in New York City wearing a giant diamond ring on her left hand. During an interview on CNN earlier this year, Baldwin spoke about his joy in meeting the New York yoga teacher. "Right before I met Hilaria, I ... lay in my bed and [said] 'this is it'...