These days, there are a lot of step families and this can cause problems with having the traditional plan. The ‘step’ parent may feel put out if they cannot sit with their partner so think carefully. This may also cause upset on the other side of the family who may feel that the step parent does not qualify to be there.
Why not try having just a single table for you and your groom with all other guests and wedding party on other tables around the room.
If you have a lot of bridesmaids and ushers, maybe have them on the top table with the two of you and have the parents on their own tables next to yours. This will avoid any difficult situations with step families or family that do not get on that well.
Whatever you choose, on the day, go with it and do not panic if people don’t turn up and you have a few spaces.
Once the meal part of your wedding is over, people tend to move around and sit on other tables to socialise with the other guests anyway.
Stay focused and do what you feel is best for your situation.
You cannot please everybody all of the time so relax and enjoy your special day.