Praise be to Allaah.
In principle, the wedding party and waleemah should be done at the time when the groom enters upon his bride, because one of the aims of the waleemah is to publicize the marriage, as it is something legitimate that should be made known, as opposed to fornication which is done in secret and is hidden – even though nowadays some people have no shame and commit haraam deeds openly, seeing no difference between halaal and haraam (we ask Allaah to keep us safe from that). “They are like cattle, nay, even more astray” [al-A’raaf 7:179 – interpretation of the meaning]. There is nothing wrong with having a second wedding party, even after some time has passed, if there is a reason for doing so. Perhaps the person who is asking this question wants to please his parents and not make them angry. He could just inform his parents, without having a wedding party, or he could invite them for a meal without having a party as such. And Allaah is the Source of strength.