Sharing an account is against TOS; you and your friend should use separate accounts. You won't get banned from this singular game alone, but if there is evidence from many games you could possibly be banned.
Got 100% accuracy.. Will I be banned

18 moves is a little suspicious but doable, and if you start getting 100% accuracy with 25, 35, or 45 moves for every single game....then it becomes pretty suspicious, especially if your speed chess rating doesn't match your longer timed games.

https://www.chess.com/analysis/game/live/60821327609?tab=review
God im gonna be banned. Normally my accuracy is actual dog shit. Me and my friend share a account so idk but.