If the grooms father is his best man, does the groom's mother sit alone at the wedding?

If the grooms father is the best man, he doesn't necessarily have to sit at the head table. He can sit with his wife close by and still toast and give a speech. Otherwise, his wife can sit with other family members. It is only for a short while during dinner anyway. I don't think there is any protocol for this situation. What everyone thinks is most comfortable to do.

Tick

Since he's serving in two roles, it would be fine for Dad to either sit at the head table as best man, or he could sit with his wife, with whom he could host his own table including his and his wife's closest friends and/or relatives such as grandparents. I think it would likely be more comfortable for him to sit with his wife, not at the head table, and to just walk up to the table and stand by the bride and groom to make a toast. The rest of the bridal party is likely the bride and groom's generation, so leave the "kids" to party at the head table.