Musar על סוכה 103:1

It is also good to cause bridegroom and bride to rejoice, as it is said, "The voice of mirth and the voice of gladness, the voice of the bridegroom and the voice of the bride" (Jer. 7:34), but one must be very careful not to amuse them with vulgar speech or jests for this type of rejoicing brings Divine Wrath. Nor should men and women mingle in the precept of causing bridegroom and bride to rejoice, for this is too frivlous. And even in mourning and during the Eulogy, the Sages said : "Let the men sit by themselves and the women by themselves! All the more is this true in rejoicings and we have learned 'Only to do justly, and to love mercy, and to walk humbly with thy God' (Micah 6:8), and "walking modestly" means — the funeral procession and bringing the bride under the Wedding Canopy" (Sukkah 49b).