Talmud for Berakhot 2:8
חָתָן אִם רָצָה לִקְרוֹת קְרִיאַת שְׁמַע לַיְלָה הָרִאשׁוֹן, קוֹרֵא. רַבָּן שִׁמְעוֹן בֶּן גַּמְלִיאֵל אוֹמֵר, לֹא כָל הָרוֹצֶה לִטֹּל אֶת הַשֵּׁם יִטֹּל:
A bridegroom who desires to recite the Shema on his wedding night may do so. R. Shimon b. Gamliel said: "Not all who wish to take the Name may do so." [If he is not recognized as a sage and a porush (saintly) in other matters, this is nothing but pride, pluming oneself on exemplary powers of concentration. The halachah is not in accordance with R. Shimon b. Gamliel. We find some of our rabbis saying that today all men should recite the Shema on their wedding night. For since in these generations we do not recite it with much concentration on all the other days, if a bridegroom did not recite the Shema on his wedding night, he would seem even more haughty, giving the impression that he concentrated at all other times except this, being preoccupied with the mitzvah.]