Thank you for the compliment.

There are no prayers established by the Sages to be recited before marital relations, so there are also no laws about such prayers. Different individuals or communities may well have composed prayers of this sort, but they are local initiatives and have not found their way into the prayerbooks.

In the area of blessings rather than prayers, the Shulchan Aruch does mention a blessing that is made after intercourse the first time with a virgin bride. However, others indicate that this blessing should not be recited. It depends on the local custom. For marital relations on other occasions, there is, to the best of our knowledge, no specific blessing. There are recommendations to think holy thoughts as part of the preparation for marital relations but this can be done without a blessing.