Is it bad to date someone three years older than you?

No, It doesnt matter much how much difference you have in years. as long as you love each other with your heart and soul. However you both should be able to understand each other and maintain a healthy relationship.

I have myself a fiance whos is three years younger then me. And she has good understanding with me. We already are in love with each other heads over heels.

People have relationships with an age difference of 20 years or more. Go figure that.