그만해, 나 남자친구 있거든

The line, explained

A stranger at the bar will not take the hint, so the heroine finally turns around: 그만해, 나 남자친구 있거든. 'Stop it, I have a boyfriend, you know.' The ending doing the work is -거든, one of the most expressive sounds in spoken Korean. It gives a reason the listener did not know yet, and depending on the tone, it can be a gentle 'you see' or a sharp 'for your information'.

그만해 means 'stop it'. It comes from 그만하다, to stop doing something, and the casual -아/어 ending makes it a command. You will hear it in every argument, every sibling fight and every scene where someone teases too far. 나 is 'I', and 남자친구 is 'boyfriend', built from 남자 (man) and 친구 (friend). In real conversation it is often shortened to 남친; girlfriend is 여자친구, or 여친.

있거든 is 있다, to have, plus -거든. Spoken, the ㅆ of 있 turns into a hard T and the ㄱ that follows tightens up, so it sounds like it-geo-deun with a crisp middle. -거든 attaches to any stem without changes: 바쁘거든, I'm busy, you see; 알거든, I know, okay. For the past, put it after the past form: 먹었거든, I already ate. Add 요 to be polite: 있거든요.

What makes -거든 special is how it frames information. It implies 'here is a fact you were missing, and it explains everything'. That is why it so often follows a refusal: 나 오늘 못 가, 일이 있거든, I can't go today, I've got work. It can also start a story, holding the listener's attention: 나 어제 걔 만났거든, so I met him yesterday, right… and the listener knows more is coming.

Deliver it with a cool, flat look: geu-man-hae, a beat, then na nam-ja-chin-gu it-geo-deun, with the last syllable firm. Then try other excuses: 그만해, 나 약속 있거든, I've got plans; 그만해, 나 지금 바쁘거든, I'm busy right now. And try the gentle version with a friend: 미안, 나 아까 먹었거든, sorry, I already ate. Same ending, completely different temperature, and now you can choose which one you need.