It is only natural that the male dog is excited as you would be if you were him. The female will want to mate too. You ask what can you do. Well the solution is to have them BOTH neutered. This is fair to them as they will cease to be frustrated and it will be very beneficial to the dog world not to produce any more unwanted pups. Please see your vet and arrange their operations. Thank you. Please let me know. Cheers.