Strangers,
hiring.

Pose as our long-lost relative at a family barbecue for two hours

Everyone's in on it except my aunt, who swears she remembers "cousin Dave". Show up, commit to a vague but warm backstory we'll script together, eat a burger, dodge specifics. Two hours, no money changes hands at the event, harmless fun. Stay in character. She will absolutely tell you about your "shared childhood".