Great question, Dianne!
Difficult to answer in brief, since so many things turn me on!! Your very question has me feeling somewhat agitated...
Silky, slinky and slippery fabrics/garments turn me on. To go shopping for something by myself or with a lover is exciting, involves revealing my feelings publicly. Others see me browsing, and then at checkout, buying... The used clothing stores usually have more variety. One can also reflect on others' choice of clothing--first to buy, then to relinquish.
My ambivalent feelings about enemas turn me on, simultaneously wanting one and knowing it will take some time, involve a few unpleasant sensations.
I connect the two by having a particular item of clothing (a black slip), that I usually put on, that act signifying that I will go through with the ritual. The build up is as intense as the enema.
Without a dominant lover atm, I take the role myself: "Put on your black slip!"
Just as starting and interrupting the flow of pee is pleasurable and good training for the prostate muscles, I find stopping and starting the flow during expelling is a turn on.
Enema plus handplay is a turn-on. Using lube and without going too far, I can be at a high level of arousal, for an hour or more. A few strokes, pause (beg! whimper!) a few more, etc. Incredible sustained hotness.
Enjoy your play together! Hope you will find things to say to him, and ask of him, that get his heart pounding.
Update: Okay, he's not the guy. Well, someday soon... maybe one day I'll find someone to give me some heart-pounding discpline.