"The Secret Lives of Mormon Wives" star Jessi Draper sent her co-star Miranda Hope some flowers ... after it came out that she was all smoochy with Miranda's ex-husband.

Miranda posted the bouquet on social media Thursday, and the accompanying note from Jessi, who said she understands if Miranda is upset with her -- and is sorry.

It looks like the flowers were delivered shortly after a blog post claimed Jessi was spotted cozying up to and kissing Miranda's ex, Chase McWhorter, at a recent party with friends.

Sources familiar with the situation told TMZ that ... it’s true Chase and Jessi kissed. We’re told it’s never happened before and was very much in the moment.

Our sources say Chase told Miranda about the kiss the next day -- and has been profusely apologizing to her ... though it's unclear if Miranda has forgiven them.

TMZ broke the story ... Jessi's husband, Jordan Ngatikaura, filed for divorce from her earlier this month, and the split is already getting nasty.

Miranda seems to like the flowers ... she said they were the "prettiest" and she added a 🙃 emoji to her IG story.