In olden days, many couples could not afford to have grand weddings due to poverty.
In a wedding, a bowl of noodle soup is given to each guests after the wedding ceremony and that was very common. When people ask “When can I have a bowl of noodle soup?” (언제 국수 먹지요?) means "when are you going to marry?" indirectly.
When I was twenties, my carrier was important so I did not think of marriage too much although my friends were married on time (early 20's ~ mid 20's). After my mid 20's, hearing this question like "언제 국수 먹지?" became a pressure. So, you may have to be careful to use... it can be fun for someone but it can be a stressful question for someone.
When I was young, I used to eat this noodle soup when I went to old type of markets with my mother... I still like the taste and I still make this for my family sometimes at home.
김망재선생 언제 국수를 먹지요? (언제 결혼해요? 중매를 해 준 사람으로서 당연히 궁금한데... )