Disclaimer: I do not own Percy Jackson, if I did, Reyna and Leo would already be on speaking terms and Calypso would not have to breathe anymore.
Piper was not a drunk. It's not her fault that men liked to buy her fancy drinks with fancy names and prices she really didn't want to know. It's also not her fault that she was in the club every night. She wasn't the one that left herself lonely for so many years, and yes, 7 years is way too long to wait for someone who is never coming back. But she couldn't help it. That wasn't her fault either. How could she control the fact that he was so damn addicting. And perfect. So, so perfect. It wasn't even his fault that he hadn't come back yet. After their impossible quest to defeat Gaea, how were any of them supposed to control the survivors? The fallen? Not that she would accept that, that he was one of the fallen. No, he was coming back to her, just like in the Wolf House. She told him to everyday, before she got too drunk, when she could charmspeak without slurring most of the words. Not that he could actually hear her, most people thought, but regardless, she would yell at that headstone everyday, but would also always leave him fresh flowers and one of the feathers she used to wear in her hair. Back when she was happy. Carefree. Didn't know what pain actually felt like. She knew now. Oh, she knew, and she felt it everyday, until it got drowned in the burning of the liqueur going down her throat, and then the sweetness of whatever fruity drink would end up getting ordered for her. And she would drink it, would drink anything, to make the pain go away, even just for a few hours. Then she would wake up in her bed in the morning, see his picture, his face, and feel the hangover, and the pain would increase by a tenfold. But by the end of the night, the pain would be gone again. Just like all the nights before.
Piper was not a slut. No really, she wasn't. Yes she stopped downplaying her beauty and wore revealing, skin tight clothes with a lot of make-up every night. Sure she would flirt with any boy in the club with blond hair and blue eyes (when she could find one with both.) And sure, she would dance against him all night, for as long as she could, until her vision blurs, and she can't stop stumbling every time she steps. But she never went home with any of them. Though they were cute, some of them absolutely sexy, none of them were him. They didn't have that cute little scar on their lip. They didn't give her a million butterflies, just from looking at her. They couldn't fly. They weren't perfect, neither in essence or for her. No one could ever compare to him. They weren't him. And no one will ever be him again. He died, even if she won't admit it. He's gone, and he's not coming back. If she wants him, she's going to have to go to him.
It wasn't Piper's fault her friends worried about her. Or as many friends as she had left, since the biggest worrier was gone. And she wasn't coming back either. Anyway, it really wasn't Piper's fault her friends worried about her. If she had her way, they would just assume she was fine and leave her alone. But they hadn't left her alone, not since the six months after some of their friends had left them. When they really did believe that she would get better if they left her alone for a bit. Now, every time she tried to convince them she was okay, they could smell the whiskey, hear the slurs and see the bottles that proved that she was not. But what could they do? It'd been 7 years and she still hadn't even started healing. They tried therapy, Piper just ran away. It took them weeks to find her again, sleeping on a park bench in New Rome, because the Romans knew what happened to her, they left her alone, let her sleep on their benches, even tried to give her a room, though she refused once they refused her the alcohol she so desperately craved. They got her home, Frank carrying her to Leo's car, renovated beyond recognition, everyone has their own ways of coping. When they reached her apartment that her dad so generously paid for, Reyna and Hazel helped her shower and get cleaned up. But still wouldn't let her have any alcohol, which Percy was busy stashing, sometimes swiping a few bottles, while the others pretended not to notice as they helped hide. That was when Piper started hallucinating.
It wasn't Piper's fault she started going crazy. Her friends realized that something was seriously wrong when she started talking to an invisible figure beside her on the couch. They took her to the doctor, who told them what they already know, she was dehydrated (alcohol will do that to you) and suffering under severe depression. They gave her pills, which for the first month, Percy, who lived the closest would force her to take. But after seeing her in even more pain from them (she had lost him again) he just started coming over for a drink. He was Piper's best friend, he knew exactly what she was going through, and therefore, she could stand his company the longest. Because yes, it was becoming difficult to stand the company of her well meaning friends.
It wasn't Piper's fault that she was antisocial. She loved her friends, she did. And she somewhat understood that they were trying to do. They were trying to fix her. But it wasn't their fault they didn't know. They didn't know that when he died, he left her broken beyond compare. He stole her heart, and when he left her, he took it with him, and what he left her with was a cold, non beating, bloody object that could in no way replace the heart that he took from her. She remembers when he first gave her his heart. It made her happier, stronger, even a bit more naive (she really thought they were both going to live), but now, all it does is make her weaker, as she slowly lets the broken pieces of herself go, to fall, not heroically like he did, but pathetically, like feathers from wings that refuse to fly, and shatter as they hit the ground.
It's not Percy's fault he let her drink. He'd seen and heard her at the cemetery, yelling and crying at Jason's tombstone every day, just as he cried at Annabeth's. But he also saw how she always left flowers and a feather for him, after getting so angry at him for not coming back, and he realized that some of the old Piper was still there. And everyday, he'd do what he felt like his obligation to Annabeth, and his best friend, who was too broken to be fixed, but still alive, and follow her to the club, let her drink and free herself of the pain, and when she was too drunk to stand properly, take her home and leave a glass of water on her bedside table (he stopped leaving pain medicine when he found out she wasn't taking them, just stashing them for something he did not want to think about. He couldn't stand to see her in pain though either, so he stopped making her take her anti-depressants, which were honestly just expensive horse shit, seeing as all it did was make her even sadder, even more depressed, so he continued to let her drown her pain and memories in alcohol and joined her in it, but always made sure to stay sober enough to make it home, not because he particularly valued his own life anymore, but because he honestly doesn't think Piper could live without him, which, is probably true, she would have been driven to extremes measures of seeing him already if Percy hadn't been there. And so they continued their routine of drinking their pain and lives away for months.