As a male dancer let me say...

First: John Travolta, Fred Astaire, and all of Broadway would be very disappointed if Dancer was a female-only class.

Second: The main difference between male and female dancing in social or performance styles is how you move your arms/hold your hands for certain movements that are basically just ‘arm flair’ and males don’t move their hips as much as females (we still move them, though). We still do all the same moves.

The idea that only girls should be dancing, and that dancing has to be all about sexy movements is completely off from what most dancing actually is. Most structured dancing is used to express song and emotion through movement, which is likely what would be used to make the dancer class - not 'sexy club dancing'.

If you're worried about guys having to wear dresses, check out the recent winter olympics figure skating events. Plenty of dance costumes to see there.