How do you call mr and mrs in Korean?
A friend of mine is going to marry a Korean husband. She knew I knew Korean and so she wanted me to translate some introductory sentences of her wedding. For example, the following paragraph:
"On the side of the son's family, I would like to introduce and invite you to the stage Mr.....and Mr.....who are the groom's twin" (아들 가족의 측면에서, 나는 당신을 무대에 .........소개하고 초대하고 싶습니다.)
But I do not know how to call Mr and Mrs in Korean. Can you help me? Thank you!

Question

How do you call mr and mrs in Korean?
A friend of mine is going to marry a Korean husband. She knew I knew Korean and so she wanted me to translate some introductory sentences of her wedding. For example, the following paragraph:
"On the side of the son's family, I would like to introduce and invite you to the stage Mr.....and Mr.....who are the groom's twin" (아들 가족의 측면에서, 나는 당신을 무대에 .........소개하고 초대하고 싶습니다.)
But I do not know how to call Mr and Mrs  in Korean. Can you help me? Thank you!

Answer

당신 sounds awkward in a social setting, and 측면 is a technical sounding word.

You can say it like these:
- 신랑 측에서 신랑의 쌍둥이 형제이신 X 씨를 무대로 모시겠습니다.
- 신랑 가족 중에서 신랑의 쌍둥이 형[동생] X 씨를 무대에 모셔 소개드리겠습니다.

* 측 = side (쪽 is another common word you can use).
* 쌍둥이 형/동생이신 = who is a twin older/younger brother.  쌍둥이 형제 is just "twin brother".
* X 씨 = Mr X.
* 무대로 모시겠습니다 = will invite (them) to the stage.

씨 is the most common title word for both men and women.  For young women(like 15 to 25), 양 may also be used.  For men or women over thirty, 님 would be a good choice - it shows more respect.  
One thing to note is that the relation is more important in such a setting, so the name and title are come after the word for relation, as in 신부의 삼촌(이신) X 님을 모시겠습니다 (I will invite the bride's uncle Mr X).  Sometimes the name might be omitted: 신부의 오빠 분을 모시겠습니다 (I will invite the bride's older brother).  분 can follow the term of relation for young people, and 님 if they're older.