Life is Strange: Double Exposure

This is unlocked in Chapter 3.
For Amanda make sure in Chapter 1 when you talk with Amanda to ask for a DATE and not just hang out. I believe that is the only choice that matters, but to be safe any time you talk with her just be friendly/ flirt.
You can be as much of a dick to Vinh as you want in any chapter.
Now in Chapter 3 talk with Amanda in Living world until the last option and KISS HER. Now go to Dead world and talk with Vinh and KISS HIM. Achievement unlocks after the conversation.

If you asked Amanda for the date in Chapter 1 you can unlock all romance achievements by doing chapter select - explore scene - spin - Nobody Wants to Drink Alone. Use RB to skip dialogue to make things quick and choose whatever outcome you want.