Where there’s smoke, there’s fire. Heather Seidel confronts husband Derek Schwartz about his smoking habit in Married at First Sight’s Tuesday, August 16, episode, as seen exclusively in Us Weekly’s sneak peek.

While on their honeymoon in Puerto Rico, Seidel, 32, tells Schwartz that his smoking is “a huge concern” for her. “I am so turned off,” she says. “Doing it every single day that we’ve been together, that to me is a big red flag.” Schwartz, 35, defends his habit by saying that many people argue “alcohol is worse.” Seidel then snaps, “I don’t get up and drink in the morning.” 

In an interview on the episode, Schwartz expresses his frustration at his wife-of-five-days’ lack of understanding. “I thought things were going well for Heather and I, but she didn’t want to listen to my point,” he says. “She didn’t want to give any credibility to what I was saying.”

The account executive then tells his wife, “I could just as easily say that you have an alcohol issue, but I think that’s jumping the gun.” Seidel, who noted in the FYI series’ August 9 episode that she would have to “wait and see” how his smoking affected her, quickly responds, “I don’t wake up and have drinks!”

Schwartz gets up and leaves Seidel sitting alone. “At this point, I just feel so betrayed,” he tells the camera. “I’m thinking that we’re in a lot of trouble.” The flight attendant seems to agree, as she adds in her own on-camera interview, “I don’t know where to go from here."

Watch the intense fight in the clip above.

Married at First Sight, produced by Kinetic Content, airs on FYI Tuesdays at 8:30 p.m. ET.

Sign up now for the Us Weekly newsletter to get breaking celebrity news, hot pics and more delivered straight to your inbox!