Check out this soft-body test render here. I want to make a tit-fuck scene in BTQ3, so i was testing some ways, to re-create a "real" soft body collisions. It looks kinda ok, i will add this effect "on top" of original breast physics, so it should looking good in the final composition. The good thing, that it uses a real object collisions, so i don't have to "fake" them at all. It's a bit "raggy" here, because of the low amouth of samples.
Also, don't forget that you can ask me your question here. I'm gonna answer them in a few days.
Check out a test render here: