For real. And if you could pin nodes or surfaces together the animation tools would actually be very good for types of simple fuck scenes most devs are doing here. But as it is, even holding a characters waist through a full penetration motion cause all kinds of clipping problems. A real shame because Iray is fucking beautiful.
It's probably the weakest part about Daz3D after the lack of collision detection: even when you attempt to lock/pin a part of the body in place, moving a different part will often pull out the lock/pin.
I did find this suggestion laborious but it actually helped to find out where I should be pinning things down to minimize problems:
In the Scenetab expand the G3 figures to show all the bones. You will see there are several extra bones in the armateur, and some of them are meant for specific types of movement. This is likely why these figures don't work as expected with the pinning function. I suggest using the scene tab with the figure fully expanded like above to find the specific bone you want to pin and select it there. Then try pinning it to see if it will work. Also make sure you are using the pinning option you need, as there are two or three of them. Right click on the Pin icon next to the bone you have selected in the scene to see the different options available.
That said, I have tried using Animate2 (when Aniblocks have been available to start with) , or BVH imports with KeyMate + GraphMate (for which I had highest hopes, but cutting and pasting on their timelines has not consistently worked as advertised or expected.) Again, even Poser can do this stuff easier out-of-the-box.
So, seeing more solid animation in Melody has impressed me - that's something DMD has taken awhile to accomplish.