I have two sites. If a visitors click my A site Adsense, and then he/she clicks my B site adsense, Would this against the adsense's rules? And how does it count for each pay?
Google sees where the click is coming from, 2 whole clicks are not going to get your banned I wouldn't worry.
What really matters is that your clicks are generated by real people, other than yourself and friends, who generally purchase or do whatever real people do after the click happens. In other words, it doesn't usually matter what your genuine visitors are doing...
If this were to happen once or twice im sure it wouldn't be an issue. But if it were to occur more often, im positive google will be suspicious. Hell, im suspicious just because you brought it up