When someone is texting you and they use * * * in between the other words they are texting the person is likely saying something bad such as a curse word and is blocking that word.
Basically the * * * is a way to censor a word that they are typing.
In some texts the * * * can mean hesitation in the person texting or for some people texting the * * * could just mean that the person is pausing while texting.
The texting person who uses * * * can be meaning several different things when they do text the * * * to you.
Sometimes it means they don't want to chat with you anymore while other times it just means a curse word etc.