"Unofficial" Dating

Has anyone else ever "unofficially dated" someone?

By this... I mean, you and him/her hung out one on one at least two to three times a week. You occasionally made out and spent the night at each others places. You and him/her have stated you both liked each other more than friends, yet you never were "officially dating". Basically, you were dating without the title.

Did you two ever become official? If so, how long did it take. How did it happen?