Charlaine gave a great answer about the magickal implications about bringing others into your sacred space during a ritual, so all I have to add is the mandatory note about Candle Safety 
Candles should never burn unattended, so if you all leave the room or become distracted, it is in the best interest of everyone- spell included- to respectfully snuff out the candles until the guests have gone home. You can then relight the candles and continue the spell as normal 
Many blessings! 