'Summer House' KJ Dillard Reads West Wilson's Post-Reunion Apology Text on Air

"Summer House" star KJ Dillard brought fans into a vulnerable moment Tuesday night ... he read a post-reunion apology text from West Wilson on "Watch What Happens Live."

ICYMI, KJ said he hadn't heard from his formerly close friend West ahead of the reunion ... but confirmed to Andy Cohen he had a new unread message from him that he couldn't bring himself to read. But, with some courage ... he read the seemingly sincere apology for all to hear.

The text -- sent after the Season 10 reunion filmed -- read ... "I wanted to thank you for your articulation and kindness yesterday despite being hurt. I've been off social and I think I lost touch with how much hurt there was. I’m incredibly sorry."

West continued, according to KJ ... "Also sending you love in regards to your mental health. You shared a lot yesterday and I know it mightn’t carry much weight now but I’m always rooting for the best for you. I know it will take some time but whenever you feel like you’re ready, lunch or a phone call would mean a lot in the spirit of healing. No need to respond, take your time."

KJ admitted reading the message was hurtful for him because he and West were so close before he and Amanda Batula dropped a bombshell that they were dating in March.

For background, KJ is super tight with West’s ex Ciara Miller ... who was backstabbed by her bestie Amanda when she decided to date West.

They all hashed it out during a tense reunion ... during which Ciara called Amanda a "snake."

West and Amanda are still going strong ... even leaving the reunion taping together days after locking lips at a Yankees game.