I too have the problem with thigh sweep, but am slowly covering it up.
These are certain things which work for me -
single legged leg presses and heavy squats on the lower half alone....(this is a killer)
these two exercises along with hack squats have given me good results.. I do not have a big thighs, but as before people do not complain about my legs being small
Try the lower half squats with heavy load and you will surely love it