No result should be deemed definitive before 6 to 18 months after surgery, the required time for tissue adjustments and scar maturation.
By obese patients, after the 8th day, the elimination of certain amount of yellowish liquid through one or more stitches may occur. This phenomenon, called lipolysis, is merely the liquefaction and elimination of residual fat next to the scar area, combined with a seroma production, without implying a complication.
You should avoid intensive movements, especially with wide open legs. The natural traction acting on the scar through walking and gravity already causes usually a scar stretching during early stages. The lower the traction on the scar, the less its stretch.
Among the infrequent, though possible, complications of a thigh lift we can mention: hematoma, seroma, infection, necrosis, dehiscence (wound reopening), keloid, thrombosis (thrombus formation within the heart or a blood vessel), or embolism (thrombus-caused obstruction of a vein).