Things are getting even more messy in the world of 90 Day Fiancé: Before the 90 Days. In Us Weekly’s exclusive sneak peek of the Sunday, September 30, episode, Rachel Bear gets extremely upset when she finds out that fiancé Jon Walters has been exchanging messages with his ex-girlfriend … and dropping the L-word.

“I saw how you told her that you really did love her, about how bad you felt [about] the way you treated her back then, as if there was some lingering closure on your end,” Rachel says to Jon as the two sit across from each other. “You never told me about.”

Jon then tries to explain that she only saw part of the conversation and the rest was about their upcoming marriage. But that still doesn’t make Rachel happy.

“I just feel like the word ‘love’ should never be thrown to an ex-girlfriend,” she tells him. “I just feel like there’s a line, there’s a boundary there. There are some things that shouldn’t be said. I don’t understand why you feel now, to go back in time, and say, ‘I really did love you,’ just before we get married.”

In his confessional, Jon tries harder to make his point. “She’s been a friend foe 18 years. We were talking about the wedding and I guess, thinking about the future made me think about the past,” he says. “While this conversation was happening, you know, I did say I loved her, that I was sorry, because I’m not that person anymore and now I know how a man should love a woman. I’m ashamed of the person I was.”

90 Day Fiancé: Before the 90 Days airs on TLC Sundays at 8 p.m. ET.