RJ Mitte's Sister Reshares Tribute Posts After His Shocking Death

RJ Mitte's sister is spreading the love her brother is receiving online ... resharing loving posts from others on her own social media.

Lacianne Carriere -- RJ's sister -- has posted several messages from people honoring RJ to her own Instagram ... sharing one in which someone called him a "big brother."

Another shows a smiling RJ at dinner with some pals ... with "Rest in Peace" written across it.

A third post is one RJ shared himself ... smiling and waving from a convertible during a festival in South Texas back in 2022.

We broke the story ... RJ died by suicide on Monday at his home in Texas.

We've since learned he was faced with an ultimatum in the days before his death. Sources tell us his fiancée, Kennedy Suarez, tried to make him choose between her and his mother, Dyna.

RJ had a very close relationship with Dyna and Lacianne. It's unclear if he and Kennedy broke up before he passed ... though we do know their relationship was on the rocks.