You saw some pictures and had sexy thoughts about them. If you see a billboard with a gorgeous model that makes you think, "Wow, what a hottie," do you think you have to let Jay know that you had these thoughts? Are you going to tell her about every attraction that you feel through the course of a day, every day? You're human and there will be people you are attracted to, some with a history in your life and some without. I really don't think this is a big deal nor cause for any alarm or action on your part. Just know that you might now find yourself more conscious about being drawn or attracted to many more people than you used to be, simply because you've given yourself permission by embracing polyamory. Those natural attractions were kept at bay by your previously mono mindset, so be prepared now for the possibility of feeling like a kid in the candy store.
Good luck, relax, and have fun!