Cheating? Need help

Jelia • ??????
So I talk to this guy we "talk" we say I love you and it's basically a relationship but we are kinda secret with cause of an age difference. So my sister got me into tinder , at first I was laughing not even talking to any guys. Then the next thing I know I started.  I mean it's totally harmless but I know he'd freak out. Is this cheating ?