if u curse someone, u need to repent in front of them and in front of God. if u 'hold it in', u only need to repent in front of God. 'holding it in' is only dangerous if u don't 'let it out' before God in repentance and in response to His love that can cast our all fear, calm every storm and renew every repentant sinner.
it is ok to then calmly go up to the person that annoyed u and explain that their behaviour caused u discomfort and u would prefer it if they did not speak to u like that in the future.