Anonymous wrote:I think that you and your SIL (who are 2 of the 3 families) should put together a short list of places you think would work and people would enjoy along with a list of weeks that would work for your families. Present them to your DH and BIL and see if that gets things moving. If it does, great! If it doesn't, well, they don't really want to do it.
+1
Some people aren't planners, OP. My husband is the vacation planner in our relationship; I'll be the one saying, "I'd kind of like to visit Argentina" and he'll be the one coming up with a list of places to go and hotels to stay in and using the airline miles to book the flight. If he sat around and waited for me to plan the trip, he would be disappointed and I would be frustrated and stressed. Also, when big groups of people like this start discussing potential vacation plans, it can be easy for everyone to sit back because they assume someone else will be taking over the planning. If you and your SIL step up to the plate, you could end up planning an amazing trip that will be wonderful for the entire family. Please don't let your resentment get in the way of what should be a wonderful gift/memory for your in-laws.