Can someone tell me if I’m being disloyal

So I’ve been with this girl for like 1 and a half years and recently a girl in my class has been catching my eye I just think she’s pretty we don’t even talk and honestly we kept catching eyes a lot not even on purpose mostly I guess you could say I just had a crush. Anyways today she kind of randomly came up to me and flirted with me Allthough I acted dry and didn’t reciprocate any of the same energy because I really want to stay loyal to my girlfriend. Anyways I told my girlfriend about it and I joked around how I should’ve smacked her and run away screaming. Anyways cut to the chase I was basically a little horny and I started thinking of that girl because well I think she’s pretty. I don’t know why but I didn’t know her name so I looked up her instagram and I didn’t go through her highlights mainly because I didn’t know if she could see who looks through them. I didn’t add her or anything I was just curious because I didn’t even really know her name but I had been thinking of her a lot. After that post nut clarity hit I felt really guilty not realizing what I did may be considered cheating and I kind of need advice. It’s not like I’d ever leave my girlfriend for this girl or anything or even flirt with her if she asked for my number I’d just turn her down.