The craziest place I had sex was at my fuck buddy's mother in law's house. Yep, her mother in law was out of town and both of our SO's were at home so we met there and did the nasty on her bed. It was a rush not knowing if someone would drive up...We would have been dead.
The craziest position has to be the one I tried the other day. I don't know the name so I'll try and explain.
The lady lays on her back, pulls her feet back to touch the bed too. So her ass was straight up in the air. Like she was about to do a somersault. Then I faced the other way, with my ass facing her, and basically did a tea bag type thing.
I had her blindfolded at the same time so she was going insane.