Some guys will only ask you out if they are sure the answer will be yes. This is applicable to all the guys who are afraid of rejection, since they have no assurance. To make him ask the big question, you should keep on suggesting how you want a date to be like or your dream wedding. For instance, you should bring up topics about people such as celebrities who are dating or just a random couple that passes holding hands. Bringing about the dating topic regularly will give him the necessary hints and it will also make it easier for him to talk on the topic therefore making him feel at ease.