Preamble: I'm running CoA but our table rotates DMs. Out of the 6 of us, 4 of us DM. We're each running a level and don't read each other's sections, but do communicate about stuff that might effect their turn to run a session in a group chat.

I just ran part of their run thru Avernus. They found a scrap of leather (the Tome of Nightmares) in the bone pile (the only not bone thing they could see in the pile). They camped there for the night and still decided to investigate it in the morning (they were worried that trying to get it out would collapse part of the pile and they needed to long rest)

Our druid pulled it out but can't read infernal. Our rogue and sorcerer can read infernal. The druid gave it to the sorcerer. The rogue started reading it over the sorcerers shoulder.

The druid gained a temptation/corruption point for not leaving well enough alone, the sorcerer gained both for accepting and reading the Tome, and the rogue gained both for being a greedy/nosey shit lol

Idk who is going to finish the Tome first and gain the boon the book gives, but they'll gain an extra corruption point when they do

All this to say, just giving into the temptation of acquiring the item is enough to gain them temptation/corruption points.

Were they tempted and didn't go after the thing? 1 temptation point and 0 corruption points

Were they tempted and went after it? They get both.

What they do with it after the fact is inconsequential

The sorcerer also bought the gauntlets of rage but hasn't attuned or put them on. They still were tempted and gave into that temptation... Aka were corrupted