Translation:Shulchan Aruch/Orach Chaim/280

1. The Laws Pertaining to Marital Intimacy on Shabbat, 2 Seifim: Marital intimacy is one of the expressions of Shabbos pleasure. Accordingly, [our Sages] determined that healthy Torah scholars, who are obligated to fulfill their conjugal duties once a week, should do so each Friday night.

2. It is permitted to engage in marital intimacy with a virgin for the first time on Shabbos. There is no prohibition because of causing pain or damage on Shabbos as a result of her initial intimate experience.