Scotty Ayre, 23, claims he dated the mother-of-three in August 2016.
"We were a 'thing' but she didn't know what she wanted so we just fell out," the aspiring model exclusively told RadarOnline.com. "It was a train wreck dating her!"
Messer, 25, was accused of drug use by her ex-husband Corey Simms on an episode of Teen Mom 2 before her 30-day rehab stint for stress and depression. Messer always denied the claims.
According to Ayre, he never witnessed Messer use any illegal drugs.
"She didn't take nothing that she wasn't prescribed," he claimed. "She's not a druggie at all! She's a good-hearted girl."
Ayre has tried reconnecting with his ex, but he claims she has not returned his advances.
"I wish she would give me another chance, but I have to let her come to me," he said. "I can't chase her."
Ayre believes Messer is ignoring his texts because she's back together with ex-husband Jeremy Calvert.
As RadarOnline.com reported, Messer and her second ex-husband posted photos together while at a bar in April.
"Just a little fun, that's all," she captioned a steamy photo of the exes. Calvert added, "Being friends with your ex shows you two are mature enough to get over the fact that you weren't meant to be together."
Although Ayre is open to getting back together, he believes it would be best if she remained single.
"She needs to focus on herself first before she needs a man," he said.
What do you think of Messer's secret romance? Tell us in the comments!
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