I would go with something along the lines of Judi’s idea…but a little something like this.
find the trashiest, and dirtiest girls you can get your hands on via something like….craigslist, or something of the sort. Explain to the girl, that it’s a gift for his birthday, and have her act accordingly. Tell her he’s already taken the room out and has the door unlocked and she just has to walk in. The bad part is you’d probably have to pay her in advance, but the good part to that is she is probably cheap anyways.
rent out a cheap hotel in the area that he lives to make him think you’ve stopped in the area to get to know him or something of the sort…you can better make the details since you’ve been talking to him. Oh and pay cash for the room, and make it out under some anonymous name.
Now that you know it’s all going down, and they are in the room, you should be prompt to make the next step. Call the police and let them know that you’re staying in a hotel room, and the people next door (his hotel room) are creating a disturbance and you have reason to believe there is prostitution going on and it’s something you don’t want your children to see. I’d make this phone call from a pay phone too.
you can add any other details you may want…such as…tell him to bring you flowers and a favorite candy of yours. say something like “By time I get over to the room you had better be ready to go” (have your clothes off and ready to go).
You’ll need to tell him you’re picking up a few items for him or something…find an excuse not to be there…..
There are a couple other ideas that would be more simple too. And less expensive on your part….here is another idea that just came to me:
Have him wait at a hotel just like before. But instead of hiring a whore to meet him, hire a real big guy who is capable of beating anyone’s ass to go over and give him a beat down. You could probably even record it “catch a predator style” like Kiev said. Instruct the guy to say some sort of catch phrase too…like “this is from russia with love”.
I suppose these are some ideas that I just came up with…use your imagination a bit, I’m sure there are ideas you may think up or work off ours.