Should I be worried about my husband's relationship with his female friend?

Dear lady..Firstly, you sound like a sensible and rational person,so the way I read it you do have an area of some concern. Firstly..your husband was totally wrong to place his friend first and go out wih her instead of you.It doesn`t matter if he has already "made plans"He shouldn`t be making any plans with her in the first place.Secondly..he lied to you about the phone number,and if he has lied to you once then he is more than capable of lying again It is not unusual in this kind of friendship that when one of the friends has a deep problem come up in their lives.they turn to the other..and that can {and frequently} does change the dynamics.It can result in them becoming much closer and even lovers..! You need to be aware of this and don`t let it get that far.It`s okay being respectful of each others friends..It`s another thing for boundaries to be overstepped and they are being over stepped.!You need to set new rules..and this will not be easy now as you have allowed rather too much to go on before. However,If this woman wants to see your husband as a friend she should only do so at your house with you present. You shouldn`t allow any more "dinners" together or any more calls at 3 a.m. Your husband knows his {and her} behaviour is not acceptable that is why he lied to you about the phone call. If there was nothing to hide he would have told you the truth.Stop them now..before it is too late.Sit down together and lay out the ground rules that any rational person would in a marriage..you are his wife..A lot of people wouldn`t tolerate what you have for one moment...and they are not jealous or insecure..they are prudent and wise! I do wish you luck