Would this be considered cheating?

I've been dating this guy for the past 2ish weeks. We've been friends for about 6 months, but recently we've been going on dates (like where he pays). We hangout a lot and when we do we kiss, we also workout together at the gym and we'll always hug and kiss there so we're kinda acting like we're in a relationship...I guess (cuz of like the goodbye kisses etc). Anyways...this new guy at the gym asked for my number and I gave it to him and we're planning on hanging out. Would this be cheating on guy #1? Even though we haven't established a relationship, it seems pretty serious.