There is an idea (which I initially became familiar with in my misspent youth from tamei sources but subsequently have seen it mentioned in tahor one's) that Shavuos is, as it were, a marriage between Am Yisroel and Hashem. Does anybody have the source for this idea and able to elaborate?
Once we've established that there is a connection between the giving of the Torah and Marriage, this opens us up for a lot of divre torah, connecting the two. Such as the one @SimchasTorah linked to, which compares the whole time period from Pesach to Shavuos as different steps in the Marriage process. Or this one here, which uses the Ten Commandments as a template for marital harmony. Or this one, which tells us how a marriage is much more than just the union of two people.