This actually depends on who you ask.
- Some will say that you have to use "get" because it is something that you haven't done yet.
- Others will say that using "it's time" or "it's high time" is telling you that the following event is overdue, and it should have already been done in the past, so you combine "it's time" with a past tense verb in the simple past, past progressive, etc.
- Still others will say that you can use both, and there is no practical difference.
I think it really depends on which verb tense you are using. When you use the simple tenses, both of them sound correct. However, when you use the other verb tenses, the past tense of the verb sounds more correct.
It's high time we got married. (sounds correct)
It's high time we get married. (sounds correct)
It's high time we were getting married. (sound correct)
It's high time we are getting married. (sounds incorrect)
It's high time we had gotten married. (sounds correct)
It's high time we have gotten married. (sounds incorrect)
SO BASICALLY... I agree with the teachers who say you should use the past tense of the verb with "high time", but with the simple tense, you can use both with little difference.
----- 원문 표시 -----
I think it's high time we got married
이제 결혼할 때가 된 것 같아
----> get married 아닌가요?