How does the Small Folk Hobbit virtue work?

Question

In the Adventures in Middle Earth Player's Guide, there's a Hobbit Virtue called Small Folk (p. 109) that reads:

You have learnt how to gain an advantage in a fight from being smaller than most of your opponents. When you are being attacked in melee combat by a creature bigger than you (very often), you can take a bonus action to step into the same square as your opponent. You have advantage on your attack rolls against that opponent, until your opponent chooses to take a step back to attack you (which will provoke an opportunity attack).

(Emphasis mine)

How does this virtue work? Because "being attacked" means the opponent's turn but "bonus action" means my turn.
We think this bonus action could be used the next turn after you were attacked by an enemy.

Answer 1

The creature just needs to be next to you for you to use this virtue

The wording there is really weird, so I sent an e-mail to Cubicle 7 asking for clarification. I personally thought the virtue was meant to use a reaction, but that's not the case.

Jacob Rodgers (who was proofreader of the Player's Guide) answered it, emphasis mine:

It is indeed a bonus action that you can take at any point during your turn if you want to occupy the same space as your opponent, as long as that opponent is one size category larger or more. Just being next to a bad guy is enough, it doesn't matter if it has or has not attacked you yet, just that it threatens you.

E-mail proof: