I would like to hear of any sources or issues with conducting two shevah brachos (for two couples) at the same meals:
- Would it be assur because of "ein Mearvin"
- How would it be done practically.
The Shulchan Aruch discusses this in Even HaEzer 62:2-3. In short, one can marry multiple women at one Chuppah ceremony and say one set of Sheva Brachot for all of them together. If one does this, he must have separate subsequent celebratory periods for each of the women individually (because of "ein mearvin"). If there are multiple weddings happening together, it is theoretically permitted to reciter one Sheva Brachot for all of them, but we don't do this because of Ayin Hara. However, if there are multiple bridegrooms at one celebratory meal, one may say one set of Sheva Brachot for all of them together.