Two threads with the view from either side:

[Cumference]

Maybe the original posters of the threads should discuss this:
(They could be either side of the couple )

Not dom but in a relationship
http://forum.literotica.com/showthread.php?t=1187399

And

Husband not into BDSM so...
http://forum.literotica.com/showthread.php?t=1183147