My ex is using a burner app to annoy me?

I'm staying quiet, I'm not replying or even letting him know I'm even acknowledging his attempts to get my attention. I've found out that he updated his profile to "in a relationship" but there has been no trace of this so called girl. I am trying to move on, I'm talking to other people and I've downloaded tinder. Which he is on also, if he's on there... there's no way he would be in a relationship. So I get a text saying;