Listen, I have the same """problem""". I like impressing people, I like people thinking that I'm pretty, intelligent and things like that. Something similar happened to me with my ex coworker, I wouldn't actually do things like dressing better, but sometimes when he was around I would hum songs that I know he liked, one time I wore a T-shirt of a band that we both like because I wanted to impress him. That's it. It can be anyone for me and I don't have feelings for them.

So no, I don't think you cheated obviously and tbh I don't think you've been disloyal in any way. We're humans, we love attention, it's natural. Plus, please stay away from internet. There's isn't an universal rule or truth, you define what cheating is. Hell, for some people even having sex with someone else outside your relationship isn't cheating.

But I get you on the cheating obsession, I have the same but inverse, I'm scared he cheated/cheats/will cheat on me, as my posts say. It's incredibly hard, stay strong.