Hello, I am here for you and am happy to respond. Give me a moment to carefully read over and consider your question.
I have been practicing couples and marital therapy for 20 years and am very impressed with the amount of thought you are giving this relationship. Most often, people proceed into a sexual affair without considering the consequences. The fact that you are so attracted to this young woman and spend so much time texting her tells me that you are very lonely in your marriage. Emotional affairs and/or sexual affairs are almost always a symptom of marital problems. You are probably getting the attention from this woman that you are not getting from your wife. And yes, you are infatuated with her; and when we are infatuated we often make decisions we later regret.
The fact that you feel a competition with another friend of hers who is your age could also cause you to make an unwise decision. So I urge you to think of the consequences of beginning a sexual affiar with this young woman, which could result in an end to your marriage. I believe you would find seeing a therapist very helpful in sorting through your feelings at this time and making a good decision. I hope this is helpful. Chat back if you need anything further and I will continue to help. If you are satisfied with my answer, please submit a positive rating. Thank you and take care, Eleanor