Hello.. Well you just need to talk and sort it out I feel... basically you both have to talk it out as in what had happened...I don't think it's related to his age he's just troubled about something probably...he can aldo talk to his close friends or his family as in what the problem is...thank you

Find out if he's emotionally low or listless, dispassionate in everything he is involved in or it is only in the physical relationship.He may be into a transient LOW phase or may be some other mood-disorder Or else it could be that he could be mercurial types, Too much repetition with a single partner may no longer be STIMULATING! FIND IT OUT FOR YOURSELF!!

Hello Since how long you have actually obsorbed this. Because it is definitely not an age factor but could be something else which is bothering him. May be he started feeling guilty or he is over stressed in the office or he could have found a new interest. Find out by talking to him and observing him closely . Then rake the necessary step required.