Joe Dever's Lone Wolf Console Edition

This is missable, but there is another trophy for the opposite choice you can make, so first time through you will unlock one of the other. So you may want to stop reading this and just play through the Rockstarn portion of the game to get this or the other. If you want to get both at once, then you could close the game when this option appears, copy your save to USB or the cloud and then once unlocking one, restore the save and choose the other option.

This solution contains small story spoilers. I have hidden them in spoiler tags. It describes what is happening in the story at the time that the gambling option appears. If you don't want to spoil it, then look out for the bottom part of this solution as part of the story in Rockstarn. I don't think you can miss it, you just have to make sure you choose the right option when it comes up.

You will be given a gambling option. One is to chose to go alone and the other is "Run towards Leandra. You'll go with her, or not at all" You must choose to go with her or not at all. Continue with the story and this will unlock.

If you choose the opposite option at the gambling point, then you will instead unlock: