While wandering around Solstheim a dragon attacked. It landed on some pillar and I shouted Bend Will at it. So it came down and let me mount. Then, just after we took off I got the dragon-disintegration animation, absorbed a dragon soul, and now I was riding a skeletal dragon? The only other time I have ridden a dragon was in Apocrypha. Is this supposed to happen? I would prefer my dragon mounts have flesh on them!

well. skeleton dragons are pretty cool

Idk about you, man, but that'd blow my friggin' mind. I want to ride a Skeletal dragon. When you got off, was it dead, or did it act normal?

I am not sure what "normal" means after riding a dragon. It took off and attacked me so I killed it, but I didn't get a soul. Is that normal?

Anyway: is it supposed to do that disintegration thing while you are riding it?

what happens when you use bend will on that one skeletal dragon in labyrinthian?

A. Yes, that's normal. For some people. Normally for me, it just takes off, flies around for a while, then leaves. It'll say "My service to you is done." and leave. To me, anyway.
B. No, that's not supposed to happen. Hasn't happened to me.

Well, I just mounted another dragon and it didn't do the disintigration thing. So I guess that was a fluke.

It doesn't work.
There are a few Dragons which aren't able to ride;
Durnehviir (sorry for the spellings), Alduin, the Skeletal Dragon in Labyrinthian, Paarthurnax, and there's one more. I forgot the last one, but yeah, there's some you just can't ride.

Has happened to me two times, I get on the dragon and then it turns into a skeleton and I get it's soul. It will still fly around and all that, but It must be a glitch of some sort, I guess.
Both times it happened was on Solstheim.