Unfortunately, going that far (to the kiss) currently ends one or more of the other romances, even if you break it off afterwards, due to a bug. Oops.
Please, tell me my rejection of Wyll at the final point ("Turn your head away") did not break up my romance with Astarion! I am not that far after the scene and would rather reload than progress with the dead romance.
It didn't break my romance with Astarion (had that cutscene with Wyll a few days ago and also chose the turn away option), patch 3 reshuffled some Astarion romance flags though (like you only get the 'you are incredible' confession after finishing Raphael's request but before talking to Araj with Astarion - otherwise you trigger the 'I wanted to thank you' confession - I personally prefer the 'incredible' one - you still need to have the Moonrise Towers infiltration quest progressed for both anyway).
I also don't like what patch 3 did to Gale on his friendship path. He was way nicer prior to the patch, now he's just a douchebag once you get his invitation to watch the stars together.