Season 3 Episode 9 "Santa in the Slush".
Santa in the Slush
In the last episode of season 4, Booth dreams while he is in a coma that he and bones are married but they are not in really.
Not sure, but I know there is the Christmas kiss (under the mistletoe, as a dare) and two in the episode where we see Bones and Booths first met.
B&B kiss throughout the 7th season but they kiss in "Santa in the Slush" so Bones can be with her dad at christmas.
4
There are a number of times when they kiss. The first time is in Season 3 episode 10 where they kiss under the mistletoe because Caroline is feeling "puckish" and somehow Brennan's gum ends up in Booth's mouth. They kiss a lot in the last episode of season 4 but that is because Booth is having a dream that they are married. Edit by LiftedHops: They now also kiss in season 5 because it shows us a flashback of how Brennan and Booth first met and they kiss because Booth's superiors tell him to fire Brennan so they realise they can date because they no longer work together (they were under the influence of alcohol at the time) Also the end of that episode Booth declares his love for her and kisses her but Brennan pushes him away and says that she's a scientist and cannot change and has not the same open heart as Booth does. She is afraid that she cannot love him the way he wants.
Three times so far that we know of. :)
Spoiler alert for episode 3x09 They kiss beneath the mistletoe as a deal with Caroline, the Lawyer, in episode 3x09, The Santa in the Slush. Spoiler alert for episodes 6x22 and 6x23 They don't kiss again until episode 6x22, The Hole in the Heart, when they fall into bed and are understood to have sleep together after Brennan admits that she is pregnant with Booth's baby, in the next episode, 6x23, The Change in the Game.
You can expect more sexual tension and grizzly murders, but also after Booth's brain tumor, Booth's brain thinks it loves Dr. Brennan and so Booth has to tell her and rumours in episode 18 that happens.
In season 6, episode 22, Hole in the Heart. After Mr. Nigel Murray was shot and died. Booth told Bones to stay at his apartment over night as she is distraught over Mr. Nigel Murray's death. Bones was so sad about Nigel that she crawled into bed with Booth. It is implied that they had sex and that is how she got pregnant.
Spoiler alert for episode 3x09 They kiss beneath the mistletoe as a deal with Caroline, the Lawyer, in episode 3x09, The Santa in the Slush. Spoiler alert for episodes 6x22 and 6x23 They don't kiss again until episode 6x22, The Hole in the Heart, when they fall into bed and are understood to have sleep together after Brennan admits that she is pregnant with Booth's baby, in the next episode, 6x23, The Change in the Game.
If you ever watched some videos or tv shows like Cory in the house there will be one episode where a rockstar needs a GF. A kissing booth just means that you must pay in order to get a kiss from that boy/girl who works in the booth