I will do it then:
We will take M1, which is the man, who danced with most of the girls around and let's choose D2 - one of the ladies, with which M1 DID NOT DANCED. However D2 danced with at least one man - this will be M2. These three exists for sure as you can see. Now let we see if the lady D1 exists.
We will start on the other way - let we assume that D1 do not exist => M2 danced with all girls with which M1 danced + one more lady (D2)... but at the same time we have that M1 danced with MOST of the girls => it is impossible => D1 exist
=> (M1, D1) and (M2, D2) exist