Can my ex’s parents press charges for an argument me and my ex had on instagram?

Can my ex’s parents press charges for an argument me and my ex had on instagram?
So I was dating this girl for about a week in a half and then I found out she kept lying to me and I messaged her on Instagram saying why did u lie to me, and then I said I’m just going to move and and then just blocked her. The only thing I did say mostly was that she’s a liar and that I’m moving on, now the issue is her brother messaged me on Instagram and said why are u harassing my sister even though I only called her a liar now he’s getting his parents to press charges on me for “harassment”, I then proceed to block him also cause I didn’t want any drama, and now my ex’s sister messaged me on Snapchat saying I better say sorry to their sister or they are going on with the charges and she is 21 and I am 18.

Justin’s Answer
I agree with Mr. Hardin. However, I will add that, if something DOES come from this, you should contact an attorney before speaking with police.