My non boyfriends ex girlfriend..

Kaylyn
This subject has been weighing on my mind for a few weeks now and I really want to get some advice and views from people who aren't involved in the situation. 
So I've been talking to this guy for about two months. Things are good, we go to the same school, love spending time together. He tells me that he likes me and would love to get to know me more. We're also sexually active.
But his ex comes in, she's always texting, calling or facetiming him. I'll ask him about it but he'll just say that it's annoying and she'll get the hint sooner or later...not once has he told her to stop trying to contact him. Not once has he told her that he's talking to someone. Even with the advice of three family members and myself to block her from contacting him, he refuses. 
I don't know what to think, I'm obviously upset with the situation but is it really my place to say anything? I just don't know. :(