Your girlfriend is correct. Case in point , Mikhail Baryshnikov,
who was extremely successful with women, including Jessica Lange.
A lot of ballet partners (male/female) are sig others or have hooked up just like cheerleading partners. It's kind of inevitable.
I guess male ballet dancers get the ghey rap because of the tights and all, but they have to be über strong to lift females over their heads gracefully.
The ones I've danced with have been extreme horn dogs, but nice.
Watch out for your gf!