Traditionally, this is the line where you write who is inviting the guest to the wedding. For example, if the brides parents are be hosting as they would be paying for the wedding. Most weddings these day aren't just paid for by the brides family. There is now more commonly a mixture of the couple and both sets of parents chipping in. Examples of this include:

One Family Inviting:
• Mr & Mrs Kelly are pleased to invite you to the wedding of

Both Families Inviting:
• Mr & Mrs Kelly together with Mr & Mrs Andrews

Inclusive of both families:
• Together with their families
• With the love and support of their parents