The phrase 'echarle una vaina a una mujer' is a colloquial expression from the Dominican Republic and Venezuela. It generally means to tease or mess with a woman, often in a playful or flirtatious way.
Examples
- Spanish: No me gusta cuando Juan empieza a echarle una vaina a mi hermana, siempre la hace sonrojar.
- English: I don't like it when Juan starts teasing my sister, he always makes her blush.