Let's face it … no one can conduct an interview like Howard Stern.

The Sirius XM radio host gets stars to open up about all sorts of crazy things, and Stern's sit down with Joseph Gordon-Levitt on Tuesday was no different.

Somehow the two got on the topic of drugs and whether the "Don Jon" star prefers drinking or smoking weed.

"They're two very different things," the 32-year-old actor explained. "Drinking can be fun sometimes, but no weed is more — I certainly do it more often … I go through fazes sometimes where it's everyday, it's not everyday these days."

When Stern noted he can't smoke pot because he gets "insanely paranoid," Gordon-Levitt said it gets his creative juices flowing.

"I pace around and have all sorts of good ideas," he continued. "I was stoned when I first thought of 'Don Jon' as a comedy … the way I use it, I absolutely think it has a positive influence on my creative process."

When Howard asked him about harder stuff, the actor said, "I don't like [cocaine]. I like LSD. I haven't done it very many times, it's so powerful. I've only done it a handful of times. You have to take care and really do it right."

Joseph cautioned, "Let me be really clear, you have to be very careful. It's extremely powerful and you should have someone whose not doing it [around]. You should make sure wherever you did get it [it's] super trustworthy and someone you know has already taken a dose off it."

Howard also got Joseph to open up (for maybe the first time ever) about his love life.

"I have a girlfriend, but I tend not to really like to talk about it in public," he told Stern. "She is not in show business."

The actor added they met through mutual friends.

"This is getting private! I don't want to — why should we talk about the personal details?"

When Howard pressed on, Joseph gave an explanation as to why he doesn’t like to go discuss his personal life.

"I get up in movies and I play other people, so when the audience is watching me in movies, I don't want them thinking about me and who I'm dating, and blah blah blah," he said. "I want them to see the character, the story that I'm telling."

As far as trying to stay under the radar, the actor shared, "The girl that I'm with, she really doesn't want to be a part of that. You can imagine not wanting to have that scrutiny."

Whoever the lucky lady is, she certainly doesn't seem to be looking for fame.

"Getting attention from girls for [being famous], I've always had a bit of a phobia about it in a way," Joseph said early on in the interview.

So does he give potential girlfriends some sort of test?

"I don't think there is one test," Joseph replied. It's kind of a case by case thing … I think I have a pretty good sense [now]."

Clearly!

More Celebrity Features on Yahoo!: