Ketubot 7b
כתובות ז׳ ב — ד"ה תָּנוּ רַבָּנַן
Ketubot 7b:11
The Sages teach that the blessing of the grooms is recited in a quorum of ten throughout all seven days of the wedding celebration, and Rav Yehuda specifies that this applies only when new people who did not attend the previous festivities come to the celebration.
תָּנוּ רַבָּנַן: מְבָרְכִין בִּרְכַּת חֲתָנִים בַּעֲשָׂרָה כׇּל שִׁבְעָה. אָמַר רַב יְהוּדָה: וְהוּא שֶׁבָּאוּ פָּנִים חֲדָשׁוֹת.
§ The Sages taught: One recites the benediction of the grooms in a quorum of ten men all seven days of the wedding celebration. Rav Yehuda said: And that is the case only when new faces who did not previously participate in the festivities came to join the celebration.