'16 and Pregnant' Star -- My Baby Daddy is a DANGER to My Kids

"16 and Pregnant" star Jennifer Del Rio says her baby daddy is a huge threat to her family's safety, so much so, she fled 1,000 miles to get away from him and is asking a judge for sole custody of their young twins.

The MTV star recently filed legal docs in Lake County, Illinois -- where she lives, after fleeing the state of FL to escape from her ex, Joshua Smith.

In the docs, the 18-year-old says she's the primary caregiver of the couple's twin boys -- feeding them, bathing them and grooming them -- so it's in their best interest to stay with her permanently.

That's not all, Jennifer claims there's definitely NO WAY she can share custody with Joshua -- as is the current arrangement -- due to their history of domestic violence.

TMZ broke the story, Joshua was arrested in 2011 after Jennifer claimed he attacked her. Jennifer was also arrested, for a later incident, when Joshua accused her of battery ... a claim she says is bogus.