Why did Arthur kiss Ariadne in Inception?

Arthur made Ariadne kiss him as a "cover up" to distract attention from other people trying to find who the real dreamer was.

It might work in real life, but not in his dream, because the subconscious [projections] were looking for the dreamer. You cannot "fool" projections in dreams, so it didnt work and her said 'It was worth a shot' meaning Arthur was just playing trick to get a kiss from Ariadne because he obviously likes her.