Grande, 25, said she cares deeply about Davidson and his health and does not endorse bullying.
"I know you already know this but I feel I need to remind my fans to please be gentler with others. I really don't endorse anything but forgiveness and positivity. I care deeply about Pete and his health.
"I'm asking you to please be gentler with others, even on the internet. I've learned through my own mistakes not to be reactive on socials so I do understand, Grande wrote on Instagram.
Davidson, 25, said he has been getting bullied for nine months despite not talking about his relationship.
"I've kept my mouth shut. Never mentioned any names, never said a word about anyone or anything. I'm trying to understand how when something happens to a guy the whole entire world just trashes him without any facts or frame of reference. Especially in today's climate when everyone loves to be offended and upset is truly mind boggling," Davidson wrote.
"I've been getting online bullied and in public by people for nine months. I've spoken about (borderline personality disorder) and being suicidal publicly only in the hopes that it will help bring awareness and help kids like myself who don't want to be on this earth," he added.
Davidson had revealed last year that he was diagnosed with borderline personality disorder.
"I just want you guys to know. No matter how hard the internet or anyone tries to make me kill myself. I won't. I'm upset I even have to say this. To all those holding me down and seeing this for what it is I see you and I love you," he added.
Grande and Davidson started dating in May, a month after her breakup from Mac Miller.
The pair became engaged shortly after but after the death of Miller in September, their relationship hit rock bottom. They ended their relationship in October.
Grande said she will always have "irrevocable" love for Davidson and if fans have any other impression from her recent work, they have missed the point.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)