Is this my fault?

I don't know why, but I've been feeling so guilty for this.... I'm currently in a relationship but I've started texting this one guy I'm strictly friends with more often. Lately we've gotten closer and he's just a really nice guy to converse with. (My bf is completely aware we text often). Well one night, we were having a good conversation and started talking about our insecurities. I was saying how sometimes it feels like my boyfriend isn't attracted to me... We rarely have a physical relationship and he hardly complements me. I know this sounds petty so I told him "Lol ya Ik its ridiculous but I just want to feel attracted to, you know?". I DID NOT MEAN FOR THAT TO BE FLIRTATIOUS AT ALL. He then responded with "This is off book, but I'm ridiculously attracted you...just keep that in the back of your mind for the distant future". In the moment, I honestly felt like nothing was wrong. The next day I kinda realized maybe he shouldn't of said it....but I still texted him anyways. Everything was back to normal again for about a week....Then last night, he never directly said it, but he made it very clear to me he would hook up with me once I was out of a relationship. This morning it dawned upon me how horrible it was that I let this continue and I basically broke down and told my boyfriend everything. He didn't seem to care all that much. I even told my boyfriend that I hated myself for feeling this way, but I am attracted to the guy. My boyfriend told me that it was "only natural" and he isn't mad at me or the guy at all, he just made sure I made it very clear to the guy that a hookup would never happen. I just feel like a really shitty girlfriend and like this is all my fault. I don't really know what I'm asking just any input would be nice.