He chose her over me?

So I’ve been dating my boyfriend for about two years and we used to the same college but he transferred this semester. A girl has recently been tweeting him and I asked him who she is and he said a friend. He also texts her every single day. I don’t talk to any males PERIOD so I asked him to not talk to her and he said no, they’ve been friends forever.. but I’m just now hearing about her. He basically said either I deal with him texting her or leave. How would you feel about it?? And it’s making me want to get a male friend of my own. I need help.