Hint: There is one only really minor difference, but it's bugging me. Which should it be?
I cursed the rain. By the time I had dashed from Starbucks to my car, I was sopping wet and the cardboard cup containing my venti double shot Americano was mushy and threatened to disintegrate.
Or: ...the cardboard cup containing my venti double shot Americano was mushy and threatening to disintegrate
Maybe it doesn't matter, hence the Nit-Picky in the title.
I cursed the rain. By the time I had dashed from Starbucks to my car, I was sopping wet and the cardboard cup containing my venti double shot Americano was mushy and threatened to disintegrate.
Or: ...the cardboard cup containing my venti double shot Americano was mushy and threatening to disintegrate
Maybe it doesn't matter, hence the Nit-Picky in the title.

Cursing it beforehand seems off a bit, to me anyway. (But then I am off so....)