I find teasing to be very erotic foreplay. I always tease my wife's clit by running my tongue and fingers all around it but never touching it. I do this for some time and it drives her mad. I spread her labia wide open, put my mouth right over her clit and breath heavily on it (not blowing!). She admits this drives her wild, knowing my mouth is right there but she can't get what she wants! This does work best when she is bound because she will try to push down onto my mouth but can't. I make her go like this for about 20 minutes to 1/2 hour, then when I finally get my tongue there she usually has an instant orgasm.

I am careful when I play a long time with her clit. We have used a ball gag at times but I hesitate using it. Although we aren't hardcore she does have a safeword for me to stop when it is too much.