I'm not sure how to explain to my ~7y/o I don't want her in someone's house

Recently a new family moved to our neighborhood. It's a younger white guy, his girlfriend (or wife?) and her brother, and the white guy's two daughters. My kids became fast friends with them. Really, his two girls became fast friends with all the neighborhood kids. One day, I let them come over and they were at my house for 6 hours - 2 of those hours were because their dad needed to go caulk a bathtub somewhere.I'll be honest, they're trashy. The dad, when he asked me to watch his kids that day, I'd known for less than 24 hours. He's not talkative or friendly. He gave me a fake number (or just didn't answer my "I'm sorry it's now over 30 minutes since you said you'd be back" texts). He asked my husband to babysit the next day.... whenever his kids come over they help themselves to our food. Whatever guy he lives with (who I think is his gf's brother) is creepy af and was leering at me when I first met them....So, of course his kids are forever asking if my kids can go in their house, and my husband and I both agree that no, they can't. We don't even like to invite them to our house. Other kids in the neighborhood are fine because I know their parents really well, and I trust them.... but not these girls...How do I explain to my 7 y/o that I don't want her to go into their house to where it's not... offensive I guess... to anyone? via /r/Parenting https://ift.tt/2uLvBvs