I like both girls but don't know what to do?

Ok, I have been talking to this girl for about a month now and we go on dates like baseball games, cedar point, etc. I like her a lot (we are not official boyfriend and girlfriend), but here is the problem, I go out to my car the other day and I find a note with a girls name and number on it. So I text it and turns out she works with me (FedEx Indianapolis Airport) which is huge if you didn't know, anyways, I have been texting her and now I am starting to have feelings for her as well. I don't want to hurt anyone here but realistically that is what is going to happen. HELP!