Having been quiet for a long while but still reading the forums :> I'd like to mention something.
A lot of discussion had been going on re the equipment.
But there is one major difference between a human and a canid member.
A canid member has a internal bone called a Baculum or a Oz bone.
Now - with this in mind it drastically alters the way a werewolf can walk, move, and if required perform a sexual act.
Why - because if one was to do a comparison between a wolf and a human and calculate the length of bone - one would be looking at about 7 inches or so. And bones cannot be bent!!
In the real world - and I can speak from experience having owned several German Sheps and bred them, and also being very comfortable with my werewolf mind set - one will always be stuck with somethings that can reduce only to a certain length.
If one was to remove the bone and thus have a more human style system, where the de-tumesent and the tumesent state are purely hydralic then one could have a very small sheath to fully hold the member and it could be neatly tucked between the legs or covered by long fur.
With the bone there will always be a certain length to deal with, and unless the section of skin that attaches the sheath to the body is extremely pliable then the sheath would have to be fully retracted till the section after the bone is reveal to move it around for intromission. Unless the act of intromission is at the angle to allow the sheath to retract.
Fitting it between the legs in a more horizonal format would not work for one has to measure the distance throught the pelvis just between the legs. And unless you want your werewolf running about with something pretty unhideable (and dangers to be caught on bushes and thorns etc)
The best diagrams or sketches I have seen are as follows
The sheath if placed on the belly pointing upwards. For the female the genitals are also on the front and more prominant around the pubic bone. Mating in 'half' form is easier face to face, and for wolf form the standard position we are all aware of can be used.
Longer fur can be used to hide this but you are looking at heavy fur from just below the navel downwards.
At the end of the day it must all come done to mechanics.. One one has decided the internal structure then fact must follow form.
As a sideline - I do make costumes as a hobby and I have been recently asked to help with an adult werewolf movie where I am trying to make things as realistic and functional as possible. The end results are looking very lifelike and what I have had to work out re the mechanics of extenstion and retraction, plus the normal urination and erectile functions has given me even more insite into the issues.
If you really want to work out how something will look.... Build It
Take Care
Marcwolf
p.s. - I will not post the links to what I am working on here but if people would like to see the step by step contruction then please drop me a line or a PM and I will give you the links.