Looking for japanese songs and found this one. https://mojim.com/jpy136351x1x6.htm
This is the line I'm having trouble understanding.
癖になっても知らないよ
Dictionary says 癖 can mean vice or bad habit, and I've learned what なる means. I'm just not sure how 知らないよ fits into this. Like "I don't know how this becomes a bad habit."?
癖になる is a set phrase that primarily means "to develop a (bad) habit", but it also means "to develop a love/taste (for something)". For example 癖になる味 refers to an acquired taste, i.e., a taste you gradually start to appreciate, like that of blue cheese or natto.
This 知らないよ means "I don't care" or "don't blame me" rather than "I don't know". This is one of the common meanings of 知らない. See: 知らない used in "I don't care"
癖になっても知らないよ
I don't care if you get addicted (to this starry night at Shibuya)!
