Male Dog in heat?

Question
Hello I have a male dog that I think is in heat. He goes up to my female dog and tries to mount her but she will not let him she will growl and bit at him. He then continues to get on her  and cries and whimpers like he wants it really badly. It is like he is just walking around horny all the time. I was just wondering if you have any idea how long this will go one and what I can do to help the situation I feel very bad for him.
Thank you!

Answer
Get him neutered-that will solve the problem,unlike people dogs do not have sex for love,it;it's hormonal and it's instincts

He'll be a lot happier if he is fixed and he will no longer think of mating-plus there's so many dogs being killed in shelters,do you really want to contribute to that?