They know as a foreigner in Korea you attract a lot of attention and they may assume that you must have many girls chasing you.
They are checking to see if you are just looking for an easy girl.
Treat the girl with respect, and don’t be too aggressive in the beginning and she will realize that you are looking for something more meaningful.
But when dating foreigner, they may want to test the waters about what the parental reaction will be before they decide on dating or marrying a foreigner.
Any meeting with the parents is a very serious event.
Every girls hates it when their boyfriend says, “I’m going back home now… Thanks for the year of free sex and being my tour guide. Well, they don’t actually say those words, but the meaning is similar. A Korean woman is very respectful, loyal and obedient to her parents and the parents, in turn, are very protective and meddlesome about their daughter’s personal affairs.