It is narrated from Sayyiduna Ibn Umar (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) said: "When any of you is invited to a wedding feast, he should attend it." And Sayyiduna Ibn Umar (may Allah be pleased with them both) would also accept invitations, whether he was fasting or not.
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 5766