느라고

'Because I was busy doing X'

-느라고 gives the thing that ate your time as an excuse for something else — usually being late, absent, or unable: 아침에 부동산 갔다 오느라고... 'I had to run to the estate agent this morning.' Every line here stops right on it, leaving the apology unsaid because both people already know it. The action named must be something the speaker chose to do, and it must have cost them the time.

Register: casual excuse