As for the topic at hand, I hold as always to the standard of "it's better not to do anything than to do something stupid." We've seen some very janky animations in-game so far for the most part--but on the other hand, we're still early in development. The best is yet to come.
Yeah. I'm no expert on The Scheduling Of Things, as my own general state of disorganisation will attest, but I would imagine that, as with voice acting, stuff like animations would be mostly done quite late in development so they have a (reasonably) final idea of what is actually required. I think I would tend to categorise it as part of the "polishing" stage than the more core development that'll have been happening.
As far as sex scenes go, one thing at a time; will there be snogging?