Warning folks: dark fic up ahead.
Regardless of your view on DiNozzo Sr, you've gotta admit, the guy must've been a jerk of a father to have as a kid. The following is just kinda how I interpreted a lot of what Tony's said across the series. Obviously, criticisms and the like are always welcome in the reviews! :)
Tony had never really had a 'home', in the typical sense.
Sure, there was a house, that he came 'home' to each day after school, but he hated it. Hated every single moment of being there. Perhaps that was a little dramatic, but it wasn't a happy home. Once his mother died, any real life from the house disappeared, as his father drank himself to the bottom of every and any bottle, and Tony faded more and more into the background. He tended to keep himself to himself, and put as much distance between Senior and himself as was humanly possible. It was clear that his father had no interest in his company, Tony had no desire to be drunkenly screamed at for something that he'd never done, or said, or even thought of, and he'd be damned if he let the maids finger the bruises and mutter in Spanish about him. It was lonely in the enormous DiNozzo mansion, and a young Tony had made a promise to himself, during another lonely afternoon, to never allow his children to grow up like this, to never become his father, to never allow his own house to cease to become a 'home'.
So when he and Ziva eventually married, and she fell pregnant, that promise was always at the back of his mind. They moved out of his apartment, bought a family home, with a pool and a garden, and Tony spent his free time personally painting and decorating the nursery, with his wife's assistance. Once his son was born, Tony spent as much time as was feasibly possible with him, even if it was just with the sleeping baby on his chest whilst he watched the game on TV. He tried, somewhat hopefully at first, to picture his own father doing the same, but couldn't. He struggled to remember a time before the drunken Senior, back when he was certain he must have enjoyed his childhood, but again, couldn't. Rather than wallow in it, he focused on putting everything into he and his son's relationship. The camcorder rarely left his hand, and Tony made sure that anything the boy did was documented. There was hundreds of photos taken, and place up around the house, much to Ziva's delight, and Tony could normally be found watching his son sleep, often falling asleep himself, head in his arms, balanced on the crib.
Ziva, for her part, didn't pry too deeply; she'd figured long ago that Tony would speak when ready. It had taken several years, but eventually he'd told her just why he was so...family focused. It had made smiling at DiNozzo Senior difficult for some time, but eventually, she realised that if Tony had put it behind him, it was not her place to drag it back. For her, it was comforting; after the horrors of her childhood, the terror, losing Tali, she wanted a peaceful, loving place to call home. Tony, for all his wooing and bravado and his reputation at work, was very different behind closed doors, something Ziva had learnt quickly to love and appreciate. At home, he worshipped the ground she walked on, and she often wound up lazing on the sofa in his lap, content to lie and let him whisper sweet nothings in her ear all afternoon.
Of course, that changed once little Tony arrived, and the pair found themselves almost at breaking point several times, this only increasing as Abi, then Timmy, joined the family. It didn't happen often, but there were moments. Once the children were old enough to be aware, during the arguments where frustrations had boiled over and usually shouting began, Tony always walked out before he even raised his voice, leaving a seething Ziva behind, screaming after him that he was a coward, and to come back and face her. It would be several hours later, usually once the children were in bed, that Tony would slip back into the house, often finding his wife on the sofa, the television on, but her mind in a far different place. He would join her, and it would be a good few minutes before she relented and shuffled into his lap, and he held her close, and they murmured soft apologies to each other. Ziva had always questioned why he chose to walk, rather than argue, but again, realised it was something that Tony had a backstory to, like much of his character. It had come out during a particularly emotional conversation, for both of them, and Ziva had never again questioned her husband's choice of action.
" My youngest memory?"
Tony nodded, his fingers pressing lightly into her skin in the soft glow of the fire. Ziva thought about the question for a moment, before a loving smile lit her face.
" I was just a child. Me, and Ari and Tali, playing hide and seek in the house, with Mother. That was a long time ago, far before any of the real...violence began."
Tony's grip on her tightened gently, and she looked at him, a sadness appearing in her eyes.
" A long time ago."
He nodded softly, fingers lazily playing with her hair. Ziva prodded him softly, changing the mood.
" And you, Master DiNozzo? Your first sailor suit? Piano lesson?"
Tony snorted with laughter, shuffling in his place.
" Me? Let me see..."
He let out a sigh, casting his memory back, and Ziva watched as his face adopted the goofy grin he plastered on whenever a particularly painful memory hit.
" My mother. It was of my mother. She was..."
He laughed weakly, eyes fixed on something he couldn't see, the grin fading.
" She was off her face. 'One too many martinis, Anthony!'. My dad, he was so angry. I guess, on hindsight, he'd probably been drinking too. I was meant to be in bed, the nanny would have gone berserk if she'd known I was up. They were stood in the middle of one of the halls, screaming at each other, both red in the face, y'know? Then my dad, he...he grabbed her by the wrist, dragged her into the bedroom, slammed the door, and..."
Tony winced, as if the memory had burnt him.
" 'Must've fallen down the stairs, Tony, mustn't I? She couldn't play tennis for days, her wrist was..."
He trailed off, eyes finding hers, leaning his forehead gently against the side of her head, breath tickling her ear, and murmured softly.
" I could never imagine...even having the thought of laying a finger on...on you or...or one of the kids..."
His voice trembled slightly as he said, and Ziva instantly turned to face him, putting a soft finger on his lips, a fire in her eyes.
" You're not him, Tony."
Tony never grew old of coming home. Of opening the door, and having excited yells of 'Dad!' meet his ears and three children demanding piggy backs and cuddles, thrusting pictures and toys in his face, and quickly retelling all of the days events. And at night, when he crawled into bed, laying next to him was the woman he loved, his beautiful wife who found his lips, smiled, curled herself around him and reminded him just how much he loved her.