Back to school.

Back to an attempt at normalcy by Jon Gosselin.

On Tuesday, the controversial father did what so many other parents did to kickstart their day this week:

Jon posted a photo of his son and daughter on their way to school.

"First day of 11th Grade!!!!" Gosselin wrote alongside a photo of Hannah and Collin with their arms around each other before the opening of the school year.

"Good Luck Hannah and Collin!!! Love Dad."

The teenagers, of course, are two of the eight kids Jon has shares ex-wife Kate Gosselin.

The former spouses welcomed twins Mady and Cara, 20, in 2000 -- and sextuplets Aaden, Alexis, Collin, Hannah, Leah and Joel, 17, in 2004.

Jon and Kate finalized their divorce in 2009... and haven't really stopped feuding since.

The latter has custody of three-quarters of her children, while Hannah and Collin have been living with their dad for about two years now.

They don't really talk to their mom at all.

And Jon has admitted on multiple occasions that he has no contact these days with Mady, Cara, Aaden, Alexis, Leah or Joel.

Just about a year ago, meanwhile, Jon was accused of assaulting Collin.

In September 2020, Collin himself wrote "my dad is a liar" on Instagram, adding:

"Yesterday he beat me up and thought nothing of it, he punched me in the face and gave me a swollen nose and I started bleeding.

"He then continued to kick me in the ribs after I was on the floor. He is a liar."

Authorities were called in to investigate the situation, never charging Jon with any crime.

The reality-star-turned-DJ eventually shared side of the story in November of last year, labeling Collin as "manic" and explaining that the teen had an episode after arguing with Hannah in the car.

After getting back home, Collin threw something in the family garage that struck the vehicle... and which set both sides off.

"He got in my face and said upsetting words and stuff like that," Jon detailled on The Dr. Oz Show.

"He tried to push past me and we got entangled and I had to do a restraint on him."

Jon went on to say that similar incidents had happened in the past.

He has claimed Collin has tried to run away on numerous occasions, hence the need to use a "therapeutic restraint" on him, as Jon described the maneuver.

“[It’s] so the patient doesn’t hurt themselves or others,” Gosselin said.

“It’s holding their arms or just keeping them from going to another position. But it’s also protecting you so they don’t punch you or any of those kinds of things."

Collin quickly deleted the post that accused his dad of assault, while Hannah was allegedly on the scene during the altercation and backed up her father's side of the story.

Kate Gosselin, however, has never bought it.

In the wake of these allegations many months ago, Kate told People Magazine that Jon should not be allowed near her kids.

"I am done hiding and will say this unequivocally: Jon is a violent and abusive person,” Kate told the outlet at the time.

When it comes to Collin, the situation between the parents is even more complicated.

The very young man was sent off to a special school/facility years ago by Kate, supposedly for some kind of learning disability.

She never revealed very much behind the basis of this decision, however, and Jon accused his ex-wife of simply sending Collin away for no reason... cutting off contact with him... and traumatizing him for life.

After Collin spent about three years at this facility, Jon swooped in and filed for temporary custody of the child.

As for Kate's insistence that Jon is an abuser?

"Kate, the message to you is to stop. Unless you don't want to have any ounce of any relationship with your children in the future. You're ruining that," he previously told Entertainment Tonight.

"It's not about me.

"It's about how they have to live their life by you making false accusations about things that never occurred."