I'm the Second Male Lead? I Got to the Female Lead First, Then Ran Off

I woke up as the tragic male side character in a sweet romance novel, and I knew my girlfriend was bound to fall for the male lead. Then the two of them would team up to get rid of me, the annoying side character. To save my own skin, I decided to strike first and avoid getting struck down. In the original plot, after my girlfriend was drugged, the male lead came to rescue her, and they spent the night together. But I wasn't about to let him have his way. I got to my girlfriend, Bai Ningbing, first, then waited for the male lead to show up. After that, I turned the tables and staged a caught-in-the-act ambush. "Bai Ningbing, we're breaking up! You're tainted. I don't want you anymore!" After berating the two of them, who were both left dumbfounded, I went...