What does “liarse con alguien” mean in Spain?

Literally “liar” is to wrap or tangle, and “liarse” is to get tangled up — in a mess, or in a relationship. In Spain, “me lié con el novio de mi amiga” means “I hooked up with my friend’s boyfriend”: a fling or affair, usually casual or messy. It’s the everyday word young Spaniards use for getting together with someone, no commitment implied — exactly the drama the speaker is confessing here.

Don’t confuse it with “liarla” — to screw something up, cause a mess (“la has liado”). The noun “un lío” is both “a mess/tangle” and “a romantic entanglement,” and “tener un lío con alguien” means to be having a fling. More Peninsular flavor in the clip: “me puede” (it gets to me / overwhelms me) and “es heavy” (it’s intense), pronounced “jevi.”