I must say that egirlky is right-on in this matter! And you definitely had some good advice, too!
All I want to add is that in any relationship, you must communicate your boundaries, and negotiate the way you want your "play" to go. And if a couple sets up those boundaries, and agrees to them, they must not be broken.
However - if any of you are into BDSM, the way Doc and I are, you will find that some ladies (and even some men) will start out saying "NO!", but can eventually be persuaded otherwise.
For example - you have a submissive, but shy, partner. You introduce enemas, and she/he is willing to try, but doesn't want you in the bathroom - totally understandable!
Your task - start slow and easy, then get more intense. The first few times, let her/him be alone. Then you can re-negotiate the boundaries - say, leaving the door open. After that works, move on to insisting your presence, but be sure to offer rewards. Say, if she/he behaves/cooperates, you will give them "X" that they really like.
It's all about working towards both of your enjoyment. It took Doc and I years to work out our boundaries to ensure our mutual enjoyment! Take your time, communicate, negotiate, and it should work out for the best!