from wat i've read in the novels, anakin only rarely go one or two shore leaves with padme. of course they wouldn't last a day 'cause obi wan needed help.

but yes obi wan did know all along, and didn't tell anyone because he was concerned for anakin and would do watever to protect him and padme.

from my knowlodge, yoda had an idea that something was up, but never said anything to confirm that he knew there was a thing going on between them.

the whole senate overthrown deal, if you listen in the movies, the dark side has a way of clouding a jedi's mine as so to be invisible to them. the darth bane novels go deeper into that btw.