It seems to me like you see he is having the emotional affair you're "afraid" he's having. What's the question? Is it fair of you to object? Absolutely! These intimate things should be special topics for you two. You should be his go-to conversation partner, his confidant, his pursuit. Not her... Obviously it is helpful that she is a highly desirable young woman (to him). She is getting this great gratification from getting his special attention and so is he. No WAY IN HELL would I ever let my husband behave this way! Are you kidding me? You are completely justified in feeling uncomfortable. Should have been uncomfortable years ago. Now what do you do about it? Find out why your husband wants someone else to satisfy his emotional intimacy needs. ☹️