Stepmom Says I Look Good

My stepmom and I have never really hit it off for as long as I remember.
Last night she came to a family gathering for my brother who had come from England to South Africa to see his new born grandchild.
I was standing in just my shorts, on the porch of the guest house with a large Savanna in hand, when my sister and my stepmom arrived.
They came ambling up the stairs greeting everyone as they went.
Well I politely greeted her with a light peck on the cheek. Then I noticed she did not move on inside with my sister as would be the norm. Instead she stood there looking at me worth a glint in her eye.
"You look very well" she said smiling. Being so full of myself I retorted "Yes I do" and she continued to look strangely at me. I was starting to feel a bit uncomfortable when she suddenly turned to go on inside.
Later I mentioned to my sister that the stepmom was giving me the once over and possibly trying to chat me up.
Well she burst out laughing saying how vain I was because the fact was that my stepmom was going blind.