I try very hard to say "No Thank You" in the kindest of ways but any kind of no seems to be taken the wrong way. It's like, why did you ASK a yes or no question if you knew you'd be offended by the possible "no" answer. It's not personal. Sometimes I just want to play on my own. Sometimes I have something in particular I'm practicing or trying to warm up. Just b/c you're a man and I'm a women, DOESN'T mean I automatically swoon at your favor.
Cute Story:
Lodini and I are shooting scotch doubles at a bar one night and we've been beating everyone there for a couple of hours. Guy comes up to me and says, "you should put you're name on the chalkboard if you want to play." I tell him I'm currently playing right now with Lodini and he says to me, "yeah, but me and my boy are up next and we'll never lose to two girls!"
(Talk about offensive!!! ... and totally the wrong thing to say to me! Lodini's face when I told her what they said was priceless

)
Lodini and I crushed them. They walked out without even a handshake cursing that girls can't play pool, we got lucky, we cheated, anything but that they simply got beat! Course the crowd might have fed the ego-swallowing lack of politeness!
It still amazes me when a man loses to a women and the guy's friends all say, "I can't believe you just lost to a girl!" Like it's shocking or something!! WTF??