Your comment that your wife is 'not picky' and she prefers strangers and hasn't turned many away made my cock so hard. My wife is the same way. Kate loves sex and she is not very picky about who she will let fuck her. I told her early on that my desire was for her to become an easy piece of ass for other men and she has.
When we first started she was seducing guys we knew, usually married guys, and having sex with them while I watched. Back then she was picky about which of our friends she would let fuck her. As she got more comfortable fucking other guys and she realized how much I enjoyed other guys getting to fuck her, she started having sex with guys we did not know...guys she met at the mall, the supermarket, the home improvement store or in a bar when she was out alone.
The more guys my wife had sex with, the more she wanted to have sex with other guys. When she could not find a guy she really liked, she would have sex with whoever was available, just to get laid. My wife has become very comfortable spreading her legs for men of various ages, sizes (height/weight) and races.
It really makes my cock stiff knowing that my hot wife will let almost anyone fuck her.