Jordan is Emma's first future husband. At first, they seem to have an okay life together, but Emma quickly picks up on the fact that he doesn't treat her well. Two examples: Her future self complains that he doesn't return from his business trips on time (cheater?), and that he spends her money. Bummer.
When Emma talks to Jordan on the phone, she says "Jordan doesn't sound like an asshole. He almost seems nice" (25.42)—she finds it hard to believe all the bad things that she's surmised about him. But in the end, we'll never know if Jordan's a jerk or not because, thanks to her phone call, we never hear from Jordan Jones Jr. again.