The 90/10 Theory

In a situation involving two people with questionable intentions, one person has to do 90% of the work (flirting, setting the stage, making it obvious that they are interested etc) and the other person is responsible for the other 10% (the final transition from almost kissing to kissing). One would think the 90% is the hard work, but it is the 10% who risks the ultimate rejection/failure/has the ability to ruin everything the 90% has worked for. Which are you?