"We've been emotional about it all day. This is the end of the line for us," Schumer said. "We will still see each other, but not as much, so we're sad. We're sad it's coming to an end, you know? We're crazy about each other."
Recently, Schumer hung out with Hawn and Kurt Russell, who all participated in a wild night of singing and frivolity, which Schumer shared to Instagram hours before hitting the red carpet.
"No one hosts a better sing along than @officialgoldiehawn and Kurt Russell!" Schumer wrote.
"That was a late night situation," Schumer joked with ET. "We were feeling the wine."
Amid the raunchy jokes and risqué situations, Schumer explained how there was one particularly revealing scene that made things very awkward between her and her brother, Jason Stein.
"I watched the movie with him -- my sister [Kim Caramele] and I rewrote this movie -- we watched it with our brother and, you know, my boob comes out in this movie," Schumer recounted. "Right before we said, 'Don't look!' We paused it, we tried to skip ahead but it skipped right to that part."
"He was like, gagging, it was awful," she joked. "We honestly haven't made eye contact since, it's very uncomfortable."
With Snatched hitting theaters this weekend, Schumer is getting ready to move on to promoting her next project --the emotional war drama Thank You for Your Service, in which she makes a serious departure from her comedic background.
"I'm really excited about it but it was [definitely] a different role," she shared. "It was totally out of my comfort zone. I was surprised I even got an audition and the script was so beautiful and amazing."
Snatched hits theaters this Friday. Thank You for Your Service comes out Oct. 27.