I think that the crease is the slight dent right at the point on the end of this line, which is dead parallel, however, the dent is lower on the left side of the thigh than in the middle of the thigh. You really should be able to see a point above the "crease" that is below the top of the knee. And personally some people call the top of the patella the top of the knee, and others look at the top of the vastus medialis. Typically I think its top of patella has to be higher than the highest point of the thigh at the crease, not just the lateral dent at the crease.
If you don't use the top of the patella, then there is no clear definition where the knee ends and the thigh starts. Also you can wear pants that dig into the crease and pull it down, but unless it pulls the whole crease below the top of the patalla its not parallel.