Been there, done that - when we first moved into our home that came with a pool.
Most of the inflatables have weight limits and when several kids are trying to climb on at the same time and are tugging and pulling they just don't last. I just considered it part of hosting guests but did what pps suggest and put the good things away when a crowd was visiting.
We purchased plenty of noodles and inexpensive toys so that I didn't mind if some were ruined. Truthfully, though, the kids were always able to have plenty of fun with just noodles and each other.