The double extension .mkv.mp4 usually means the file was originally an MKV and was renamed or converted. If you are uploading this to a platform, it is best to rename it to just Happy Ending.mp4 to keep it clean and professional. To give you a better draft, could you tell me: What genre is the video (Romance, Comedy, Thriller)?

"Just finished watching 🎬. No spoilers, but it definitely lived up to the name! If you’re looking for a feel-good vibe tonight, this is the one. #MovieNight #HappyEnding #MustWatch"

"In a world where every story seems to end in heartbreak, one person is determined to find their own version of a perfect finale."