Here is a great article by LiveTantra.com about ejaculation and Tantra.
During a Tantra massage it is extremely important not to be focused on the orgasm. In my Tantra massage I want you to become aware of your sexual energy and how it moves through your body and how you have control of it also. This is especially a great practice for any men who are premature ejaculators but will be useful for any man.
Please have a read, it is full of great information.