It’s more important to have a pleasant relationship between the in-laws, so while etiquette dictates that the host of (paying for) the wedding is listed at the top of the invite you may want to find a compromise that makes everyone happy. Here are wedding invite guidelines:
The first line of the wedding invitation is the “host line” which means that whoever is hosting the wedding is listed in the format of:
Mr. and Mrs. John Smith invite you to…
When a parent is not hosting the wedding but would like to be listed on the invitation you can include them after their child's name in the following way:
Daniel Johnson
son of Jack and Susan Johnson
If the hosting parents don’t really care if they share the hosting space with their future in-laws the hosting line would read:
Mr. and Mrs. John Smith
and
Mr. and Mrs. Jack Johnson
invite you to…