If your business offers some accommodation options for male or female only, it's possible to ask the guests to define their gender. If you don't offer any gender specific accommodation or activity options, you can deactivate this feature.
1. Click on Settings
2. Click on Frontoffice Settings
3. Go to Check out and Guest Details
4. Thick the box if your business doesn't have any gender specific accommodation options
Now the booking engine only asks the number of the guests.