No one does it better than James Franco as proven by co-stars Selena Gomez. In an interview with David Letterman, Gomez opens up on how James Franco had surprised everyone on set including her. Things went definitely creepier with Franco on set and Selena explains why.

Given James Franco is an Oscar Academy Award nominee, Franco is one to take his movie roles pretty seriously. In fact, Selena Gomez can vouch for that. In the stars' latest film, "Spring Breakers", Selena is one fourth of the girl group who goes on spring break and in a dramatic turn of events get caught up in Franco's world of sex, drugs and alcohol.

"He stayed in character the whole time and luckily for me, my character was creeped out by him, because I genuinely was at first," stated Selena during her stint on David Letterman's "Late Show" on Monday.

The situation went even more uncomfortable for Selena when four weeks into shooting "Spring Breakers" James Franco suddenly appeared, dread locks, tattoos, gangsta-styled and all.

"We shot the movie for four weeks, then he came in and walked on set as his character and freaked me out," explained Gomez, adding "That's who I knew, until we started doing press and I realized he's one of the most intelligent people I've ever met."

Well, anybody who would be around a drug-dealing and gun-wielding James Franco would be genuinely scared and uncomfortable. Of course, for Franco all this was for his role. Franco is known by his Hollywood friends as completely goofy, funny and an all-around great guy of which Selena also happened to find out late in between shoots.

"He's really nice, I promise. He's great," said Selena.

Apart from Selena Gomez, Ashley Benson can also vouch for James Franco's inner sweet guy. Late last year, Benson and Franco were spotted cuddling and kissing. Then again, the two stars were spotted four days ago getting all chummy at the movie premiere after party.

As for the film, "Spring Breakers" has already aired in theatres nationwide and the reviews are buzzing with great feedback. Harmony Korine has truly made an awesome comeback and he has his star-studded cast to thank of which includes Selena Gomez, James Franco, Vanessa Hudgens and Ashley Benson.

Check out the slideshow to see more of "Spring Breakers" promotional posters.