Levi Johnston wants full custody of Tripp, says Bristol Palin's reality show shows she's unfit

Levi Johnston believes Bristol Palin is a terrible parent and the proof is in her reality show in which she lets their son Tripp run wild, talk back, curse, and show no respect to his elders. So Johnston has decided to take action and seek full custody, TMZ reports.

On Bristol Palin's new reality show "Life's a Tripp," her and Levi's son has been a little ball of trouble and in one recent episode, even called his aunt Willow the f-word.

During the same episode, Bristol admits, "I'm doing a terrible job disciplining Tripp."

Now, Johnston's had enough, telling TMZ, he's been watching the show and is "disgusted" by his son's language and behavior. Johnston says his son is on a "downward spiral" and getting "no real parenting."

Johnston tells TMZ, Tripp "deserves a better family" than what Bristol and the rest of the Palins are providing, adding, "I love my son more than anything and I will do whatever it takes to make sure he is raised the right way."

To ensure that happens, Johnston dropped by the courthouse in Wasilla, Alaska this week to pick up all the necessary paperwork to obtain full custody of Tripp -- and he plans to file it ASAP.

TMZ's calls to Palin were not returned.