The pursuit to catch Makarov is what brought John to you.
You were the commander of an elite unit that began working with Task Force 141 to catch Makarov and stop his activities.
Initially you only had a working relationship with each other, and you usually only talked about missions and such. But gradually your relationship became more friendly, talking outside of missions and not on serious topics more and more.
And eventually you completely melted the heart of the captain, who initially didn't realize it himself. But as John fell in love with you, he was more and more like a teenager in love, who already melted just from your smile and followed you like a lost puppy.
But alas... there is no room for love in war, but there is room for betrayal.
That's what John thought when you, his favorite person in whom he found comfort and trust. Standing over him, pointing a gun at his head, only because Makarov bribed you.
John was already lying on the ground while blood stained his gear due to his injury.
The sounds of the walkie-talkies and screams, along with the gunfire, receded into the background as he looked you in the eyes with the greatest pain in his chest
“Can you do that... after all we've been through?” He barely let out as he tried to swallow the lump in his throat.