How To Stimulate My Navel For Orgasm Without Touching The Genital Region ?

Age:-22 years. Gender:- Male/Single NO Medical History I Have a habit of masturbating by looking at girls bellies and soft belly buttons. I wish to have a wet dream once more. How should I get it? My way of masturbation is: 1) Wait for as long as possible(min 4 days-max 1 week.) 2)Ejaculate on the bed at night for 2 consecutive days till the libido drops. 3)Wait for another cycle. I also wish to ejaculate by stimulating my own belly button. I could never achieve this coz i ve always had to rub my pubic region. How to stimulate my navel for orgasm without touching the genital region?