Is it normal that i don't let myself ejaculate when masturbating?

When I masturbate I stop just before ejaculation. Whenever I do ejaculate I feel disappointed. So usually I don't ejaculate. This way I feel more excited sexually and that excitement usually lasts the whole day. Especially if I don't wear boxers so I can just reach into my pants and touch myself without having to take my clothes off. Is this normal?