I have some concerns with the OP's comments hinting at Ken's roving and Barbie's hangups. Others commented on each, but no further details emerged. The concern that Ken is not a master if his genitals is very valid. This is both a health concern because of potential diseases but also an emotional concern if his penis is calling the shots. (*rimshot*)
The original mention of Barbie's hangups made me think more of what her preferences or experiences are as a lover more than what her issues with poly/open might be. There's no actual reason I'd get that sensation, but it was there.
Given the OP's good news update, I'm not going to prod at either further. If what you have is working for all involved, then I wish you the best going forward.