What do you considering cheating??

Would love to hear feedback about what you all believe is considered cheating... been feeling tension between me and my boyfriend lately so when he went to sleep I went through his phone and found some conversations he has had recently with girls on his snap chat and read that they have sent him some pics and he basically said he likes to look but it wouldn't go further... she asked if he thinks about her when he has sex with me??... I'm very faithful and would never cheat he has said the same but isn't this considering cheating??? Im confused and have no clue what to do 💔😢 and even made plans to meet up with this girl for lunch .... not sure what to do?.. any advice??