and still young and attractive, after 15 years of marriage the relationship as much stable as it may be may be getting boaring and a man may seek excitement somewhere else .. this may lead to something or may lead to nothing ...

My advise is to keep an eye from distance, give more attention to your husband, do enovative creative things to revive the love and hope things will improve ..

Make him feel loved and cared for, approch his manhood and appeal to it ...

And if things develop, do not confront him with your findings but rather question his behaviour and ask him hy is he closin the screens when you approach him and ask him if he is hiding anything from you ..

Good luck

"The best way to predict the future is to create it".