<human>: Can you give me a shortened version of the text?

We have been dating for 3 years and a few months ago I was sitting next to him and saw him get a text from a girl who's name I didn't recognize he quickly closed the text and we went on with our day but it was very odd the way he reacted and made me nervous so I approached him about it later that night and he said she was just a friend, but it came out that he had been friends with her for months and had avoided mentioning ever hanging out with her by always saying he was just hanging with the guys when she would be there too. It freaked me out that he lied to me especially for a long while but we got past it and made up. I also told him I was upset that he felt the need to lie over just being friends with someone because that doesn't bother me. A month goes by after that and everthing is fine between us and we happen to run into this girl while at the movies and he acts very very nervous and jittery when we said hi to her. So fast forward another month to now where I'm noticing he has been snapchating and texting this same girl a lot. She is even his best friend on snapchat. He talks to her about all the things he enjoys and has nicer texting conversations with her until two in the morning while he only bothers to text me one word replys most of the time. I'm ashamed to say I know these things from snooping on his phone but I got suspicious when he was being very protective over his phone, grabbing it out of my hand when I would want to just borrow it to look something up online or if he was driving and received a text I would offer to type in whatever he wanted to say in reply to someone so hes not texting while driving but he would grab the phone away. I was put off by that behavior, I have nothing to hide and let him borrow my phone for anything and to type while I'm driving. I just wonder if I'm overreacting or if this behavior is a red flag for emotional cheating and maybe my boyfriend may or may not even realize he's emotional cheating.
<bot>: boyfriend may be possibly emotional cheating with girl friend through texting and snapchating. Don't know what to do and am afraid of coming off as overreacting, untrusting and such if I bring up my feelings