Setting boundaries with neighbor kids

A new family moved next door to us last fall, and my three kids get along great with their two. I'm so, so happy my kids have friends close, but this summer has brought an interesting problem.We purchased a membership to our neighborhood pool, and our neighbors didn't. Members have to pay $3/person for guests each time. We go to the pool frequently, and my kids often invite the neighbor kids to come with. We've been paying their entrance fee so far.It's a small fee but it adds up fast, especially if we go 3-4x per week. I hate being a grinch and telling my kids they can't invite their friends, but I don't want this to go on all summer. I was thinking of telling my kids they could invite their friends twice a week and that's it - only problem is that it's awkward when they're all playing together and my kids are like, "it's hot, let's go to the pool..."Anyone encountered this before, or have ideas? via /r/Parenting http://ift.tt/29hZ863