You can wear my shirt, pretend to let you win that FIFA
FIFA is a soccer game on gaming consoles and sometimes, after a game, the opposing players will give each other their shirts. Gambino is just mentioning regular lovie dovie stuff here though. She wears his oversized shirt after sex (maybe, see below) and he intentionally loses when they’re playing FIFA, so she feels special.
To help improve the meaning of these lyrics, visit "Make It Go Right" by Childish Gambino (Ft. Kilo Kish) Lyrics and leave a comment on the lyrics box