Avengers 2 Black Widow
Scarlett Johansson didn't expect the romantic storyline Black Widow has in "Avengers: Age of Ultron." Marvel

“The Avengers: Age of Ultron” will introduce new villains like the Vision, new heroes like Scarlet Witch and even a new couple. It seems the sequel is going where the first film didn’t and is adding a romantic storyline with two team members. Black Widow (Scarlett Johansson) and Hulk (Mark Ruffalo) will get much closer in the Marvel film.

This might be shocking to fans who thought Black Widow might develop a romance with Hawkeye (Jeremy Renner). Johansson even told Rotten Tomatoes that the arrow necklace she wore in “Captain America: The Winter Soldier” was for the archer.

“I think that may have been my little nod to Mr. Jeremy Renner's Hawkeye,” she said last year. “I guess you could interpret it in different ways, but we thought it would be nice to have something that was a little bit personal for the Widow. You know, you kind of forget -- I think because she's so, she's such a bad--- -- you kind of forget she's still a woman and that she has her interpersonal relationships and life outside of work.”

It was a choice on the actress’ part, so she obviously was assuming there was something going on between Black Widow and Hawkeye. Johansson was a little surprised when she found out Natasha actually was going to romance Bruce Banner. However, her love interest wasn't as thrown by the reveal.

“I did know when she showed up and she found Banner in the middle of India that something was happening between those two people,” Ruffalo told Black Tree TV.

“I just thought I was there on a mission,” Johansson admitted.

Director Joss Whedon acknowledged that a Black Widow/Hulk romance is unexpected, but he thinks it works. “They're an unlikely pair, but there's something about the two of them that neither can deny,” Whedon told Digital Spy.

Ruffalo clarified that it’s the unexpected parts of “Avengers: Age of Ultron” that make it so exciting. “The turns that you get to make are surprising. To throw a romance in the middle of this end-of-the-world thing with a bunch of humor and some great action sequences is like -- that’s pretty clever,” Ruffalo explained.

Fans got their first glimpse of the romance in earlier trailers, but the latest sneak peek video for “Avengers 2” show Black Widow as she calms down Hulk. It seems Natasha can access Bruce even when he’s green.

Watch the sneak peek from “Avengers: Age of Ultron” below:

“Avengers: Age of Ultron” hits theaters on May 1. Are you excited for a romantic storyline with Black Widow and Hulk? Sound off in the comments section below!