The 23-year-old Teen Mom 2 star spoke to Radar Online after Griffith's supposed e-mail was linked to an account on the extramarital affair site. Over 23 million users' personal details were exposed after the site was hacked this month.
"Once a cheater, always a cheater," Evans declared. "I think he embarrasses himself and whoever associated with him, especially the girl he's with now because supposedly she doesn't believe in sex before marriage. But Nathan does."
Griffith initially denied the e-mail address was his, but later said he "simply didn't want to comment." A source confirmed the e-mail is indeed his, and told the gossip site Griffith made the account in May or June while on a break from Evans.
"The only 'friends' or support system I'll ever need in life is my family," Evans tweeted after the news broke. "As long as I have them nothing matters. #FamilyFirst."
Evans and Griffith shared a volatile relationship as a couple, and ended their engagement again in July. The pair share 14-month-old son Kaiser, and the reality star is also mother to 6-year-old son Jace with ex-boyfriend Andrew Lewis.