Meeting for drinks

My husband and I have been married for almost 9 years, and right now are down to one car. (mine) I have to take him and pick him up from work until he can get a new car. We got home the other day and he asked me if he could drive the car next Wednesday and come home late because he apparently told a former advisee/student of his that has apparently never had been out for drinks before and told her that when she graduated that he would buy her her first drink. (My husband is a college professor) He has told me no other information about this woman except that she lives in an apartment and doesn't drive so that he would have to go and pick her up and take her home afterwards. I was also told she has a boyfriend? Should I be concerened? Of should I just try and trust him that nothing is going to happen?