Mine was this morning - really trivial - my husband and I had an early night last night as I had a bad headache. About half an hour after going to bed, I heard his mobile ringing downstairs. He was asleep. I decided to ignore it as I didn't want the palaver of him starting a conversation just when I was nodding off (we are middle-aged landline users so if it had been anything important they'd have rung back on the landline).
This morning my husband remarked 'Oh, (random friend) rang me last night, and I pretended this was news to me, simply because I couldn't be bothered with the longer explanation that I'd heard but ignored the call.
What was the last lie you told, however trivial and inconsequential?