The Big Bang Theory, Simon Helberg The Big Bang Theory, Simon Helberg

On Thursday's The Big Bang Theory, Howard (Simon Helberg) popped the question to girlfriend Bernadette (Melissa Rauch) — or rather he was about to before she abruptly cut him off to accept. Helberg, however, heard all fan questions as he live-tweeted the episode and answered queries about everything from his wardrobe to his on-screen but never-seen mother.

The Big Bang Theory: Howard makes a "simple and sweet" marriage proposal

Does the cast ever improvise on the show? Negative. Half the time they're spewing complicated science terminology and, according to Helberg, "we're not that smart." "We couldn't make those lines up," he said. "The writers are brilliant and we all say it word for word.

Who breaks the most during tapings? "Kunal [Nayyar] probably cracks up the most during tapings, but we all break from time to time," Helberg said.

How does he get into Howard's trademark skintight pants? It's apparently a team effort. "I often need assistance getting in & out of those pants," Helberg said. "Luckily there are well-paid women to help. Lucky for them." As for the rest of Howard's garish and vintage ensemble, the actor revealed that there are probably more than 100 giant belt buckles in his wardrobe room. One thing he kept mum about: the story behind Howard's alien lapel pin."Only our costumer and I know its meaning. Ha-ha-ha. It's not a dirty secret, just a juicy one."

Check out photos from The Big Bang Theory

A Big wig? Howard's rigid, helmet-like 'do almost seems too good to be true, but Helberg says he's not donning any fake follicles. "I don't wear a wig," he said. "Not yet. My hair is flat-ironed, however."What is his favorite episode? Of the ones that have aired, Helberg picks "the road trip episode with the science conference at the end and Rick Fox, etc." Of upcoming episodes, he selects the one where he breaks the news of his engagement to his overbearing mother: "It's not so easy." (Click here for more scoop.)Speaking of Mrs. Wolowitz... will we ever see her? "Would you really want to see the woman behind that voice?" Helberg wrote.