Sexual partners will naturally have to be told because, covered or uncovered, the stoma or pouch will be apparent during intimate moments. You should tell a prospective marriage partner, because being open and honest is important to the success of any marriage. In addition, the reaction to your disclosure gives a good indication of the person's feelings about the whole you. You can pick your time to tell but it seems better to tell early in a relationship. This not only relieves your anxiety, but also if there is an adverse reaction the letdown is not as harsh as it might be later.
Most people prefer to tell at a time when there is a clam and understanding mood with their partner.
When you explain the surgery, do it clearly and confidently, with self-assurance. Start with a simple explanation. You need not be too detailed and technical at this point. Emphasize that this type of surgery was necessary and that managing your ostomy does not interfere with your activities and enjoyment of life. People do not fall in love with, or like, everyone they date.