The model and actress, who became romantically linked to the One Direction star last month (Mar16), shares a seven-year-old son, named Roman, with her ex-husband, Ididia Serfaty, who she divorced in 2013.

Roman and his dad live in Arkansas, while Jessica, who moved to Los Angeles after their split, pursues her career in Hollywood.

Ididia, 30, claims Jessica hasn't seen their son in months, and instead of having Roman fly to Los Angeles for monthly visits, she prefers instead to just see him for six weeks during his summer holidays.

"It's not easy being a single dad," he told "It is hard - it is a sore subject for me.

"I want her to be a mum. I grew up without a dad - my parents lived in L.A. but when they got a divorce my mum moved to Arkansas and my dad stayed in L.A. and hardly ever saw us."

"We saw him on our summer vacation - same as Jessica," he continued. "That's the source of my hurt. I deeply wanted more than that for Roman. I don't want Roman to have what I had - I want him to have more than what I had."

However, Jessica, 25, insists she would love nothing more than to have both Ididia and Roman move to California, so they can share custody and truly co-parent their child.

"There's not an ounce of me that doesn't want Roman to be out here - that would be the ideal dream for both of them to move out here," she responded. "The past couple of months have been looking really good (and) I feel we're coming close to the time where he is going to come out here with Roman and we can co-parent again."

The Blood Brothers actress, who also competed on Tyra Banks' modelling show America's Next Top Model, understands why her ex is frustrated by the situation, but she is adamant she is doing her best to build a better life for them.

"I know he's frustrated and I know it's hard for him but we are both trying our best and that's what it comes down to," she continued. "I don't want people to think that I'm not involved in Roman's life when I am - very much so - I send him kid books and I buy the same ones so we can read them together on Face Time (video call).

"Even though I don't see Roman every day we chat, we Face Time and talk on the phone every other day."