Watch: Joe Biden gets testy with Iowa college student, grabs her by the arm over question about gender

Democratic presidential frontrunner Joe Biden expressed his frustration toward an Iowa college student in front of a crowd of onlookers on Friday, grabbing her by the arm after she pressed him to explain his answer to a question about gender.

What are the details?

Biden was approached by the student — a field staffer for Turning Point USA — who asked the former vice president, "How many genders are there?"

"Pardon me?" Biden replied, before being asked the question a second time. "There are at least three," he responded.

Undeterred, the student pressed, "What are they?"

With that, the 2020 White House hopeful told the student, "Don't play games with me kid," before reaching out, grabbing her arm, and saying, "By the way, the first to come out for marriage was me," presumably referring to supporting the legalization of gay marriage.

Anything else?

Biden has taken a lot of heat this election cycle over accusations of him inappropriately touching women in the past. While most of the recent allegations have been characterized as unwelcome signs of affection, Biden's physical contact with Katie did not appear to be friendly in nature.