When an teenager becomes insecure about her boyfriend’s friendship with their female road-trip companion, she decides to make him jealous by inviting a dangerous hitchhiker along for the ride.

Check your spelling.

Too many pronouns. Can’t keep track of who’s who in relation to whom. Why so vague about the other woman? Is she a hitchhiker too? Or a mutual friend? Identify and summarize the relationships simply and clearly.

Don’t tell us someone becomes insecure; tell us she IS insecure. Don’t tell us what she decides, tell us what she DOES. Loglines should be active present tense just like the script.

Never start a logline with When. Start with the protagonist, then provide the antagonist, conflict, & stakes.

Why would she deliberately invite someone dangerous? Doesn’t make sense, makes her look stupid. And if she’s insecure, why would making him jealous be an improvement? She’d want to change herself to make him more interested in her, not bring in someone else to further distract him…how does a dangerous third wheel promote jealousy anyway?

The whole thing is unclear and makes no sense. What exactly is the story here? It’s also choppy and unwieldy as a sentence; it needs to flow.