Thanks for the reply.
I cannot agree more with your concern , but as i said earlier, this incident can be a mere joke of sorts or shear curiosity or can be a sexual fixation that your husband may be harbouring for years and the fact that you noticed it after 5 years , makes it more against him being gay.
Also , by your own admission , he has never shown the typical traits and there has been nothing unusual about his interactions with men, all these years. And i am sure you would have noticed something more about his sexual orientation , had that been the case , since you have been married for quite a long time.
But having said that, i would suggest you to talk to him about the whole incident ,in a very calm and friendly way, without drawing any hasty conclusions or making direct allegations, as this may be detrimental for your relationships.Try to make the conversation casual, try to sound as if you are just being curious about him seeing that website, and choose a time to strike such conversation when he is in a good mood and you two are alone as it can be embarrassing for both of you if such conversation is leaked.
At this moment , i would not advise you to seek help of a counsellor as your husband deserves a fair trial in the form of a private, direct and understanding conversation. Depending on the outcome of your meeting , then you may decide on seeking professional help. But i hope that option never arises and your doubts are met with strict No to your question, which i believe what you desperately want to hear.
I wish you all the best .
I hope my answer serves your query according to your satisfaction.