[Tiber]

Have done standing cowgirl before, key thing is the girl must lock her hands around your neck cause you have no hold on her as both your arms are supporting her by holding her thighs.

The girl was petite and she really enjoyed it, as in that position, can touch her gspot firmly and she came really fast.
As she was petite, there was no stress in holding her up and my neck was ok with her hold.
Size of the girl and strength of you back, lower and neck will be the determining factors on whether can pull it off.