European visas- returning in a certain amount of time

If he uses his full 90 days, he has to wait 90 days.

You must wait until 6 months after the start of the 90 days. Has he already started visiting you, or is he coming soon? If he is coming soon, he will not be able to visit you for Christmas. (However, you could go to London and meet him there! That is out of the Schengen area and the 90 Schengen days do not matter). Say he arrived in Germany on May 15. On December 15 (or maybe a few days earlier, I've read through all the Schengen information but don't recall whether it is 6 months or 180 days. If 180 days it would be December 10 or something), your fiance's 90 day count will start over, whether he reached 90 or not. He will start over with a clean count. It does not have to be 90 consecutive days. He could be in the Schengen region from May 15-July 15, and then come back in October for a month, and his count would still start over on December 15 because it is 6 months from the entry date and thus the start of his 90 allotted days. So if he arrived in early May, he would be able to visit you. Otherwise, he may want to only stay for 80 days and then come back for 10 days around Christmas, if spending Christmas together is important to you. Or head to London, Turkey, etc, instead.

If you're American, visit the US Department of State website for the most accurate, current information.

Thanks, that's the info I needed!