This is not so unusual. As many dog owners will have witnessed, even bitches often attempt to mount other dogs, or furniture, and it therefore seems that many domestic dogs are slightly lacking in their instinctive ability to breed effectively.

There are steps you can take to assist in the mating process, but it may not be very pleasant! What you need to do is basically guide your dog towards where he should be. If your female is receptive, you can easily lift your boxer into place and encourage him. If and when he dismounts simply move him back. Good luck!