No kidding. There's something very reassuring about the person you pay for sex not knowing your real name, address, phone no. Also with AW/UKP you have a reasonable idea how far she will go and if she;s any good at it.
TRUE STORY
For a very short time I was in the bed of an absolute stunner; half scandinavian, startling natural blond, slim, big boobs, even features. She is by someway the prettiest civvy I every slept with and remains in my top 5 against some very stiff professional competition. She was the kind of women EVERY man looks twice at when you walk down the street; I found it totally intimidating.
Separated by several years I also previously dated a mutual friend - who told me said stunner confessed to her that when stunner was travelling abroad she was having a great time, wanted to stay longer, ran short of money and got chatting to an older guy in a bar (Thailand as I recall). Long story short he offered to fund the extension of her trip (not huge numbers) for a nights company; she accepted. According to the version I heard she also reported it as the single most satisfying sexual encounter of her life.
I doubt this will work with someone you have an ongoing relationship with and think Apu is going to get burned. But, with a chance encounter, this one stays up my sleeve.