Cheating or just friends

Shae

My boyfriend and I have been to together a little bit over a year now. And at his second job he is training a new person and its girl. They have only known each other for like a week and they text each other everyday and tell each other good morning and goodnight they both swear they are just friends. I went through his phone while he was sleeping and yeah they just as friends but he talks to me less with less words in texts and barely any emojis and he tells her he is bored at work and he blows up her phone when he knows she is working. And he changed his Facebook password and he wont let me see his texts. And this morning the messenger app was acting up and he couldnt text her and he got super sad that he couldnt text her. I asked him what's wrong and if he was okay amd he said no, his mood changed immediately after he couldnt send a text to her and he was trying really hard to fix it so he could text her. And when he finally was able to text her he said to her he was really sad that he wasnt able to text her bc he thought she blocked him. He said they are just friends.. and I want to believe him they are just friends but he talks to her more than me and using paragraphs with her and not me. I have talked to him about this and he just asks me if I trust him. And I say yes but the more you ask that the more i question it.