Help, neighbor kids invading my space!!!?

Okay, I'm not sure where else to post this, this looks close enough. I am a SAHM of 2 children under age 3. Recently, 2 new families moved into the duplex next door to me. All together the adults have 5 children, 7 on the weekends. After they moved in, I noticed them spending long periods of time outside (the kids) playing. Only problem is, they have ZERO toys, no swings, slides, pools, nada. My children are very blessed with lots of toys so I felt bad. I decided to give them an older slide and teeter totter, but the next thing I know they are standing at the fence when my kids and I are outside begging to come in our yard to play. I thought it would be greedy of me to tell them no, so said okay. Ever since that day, they come over every time we are outside. They are wild (like most kids) and expect me to help them constantly. They ask for snacks, drinks, and to use my bathroom. If they have a problem, they ask me to do something like I'm their mom. Now keep in mind, ALL the parents are at home with their doors shut, never coming outside to help. I guess they expect me to babysit their kids while they sleep, watch movies or whatever. My question is, what should I do? Would it be mean for me to send them home? I'm sure they would just stand there staring and asking to play again. I've never had this happen and am very stressed! Also, there is a school playground a few blocks away, I suggested they go there. They just stared blankly at me.