My sister is hot and I am not

I've always been overweight, at least since high school. My younger sister, is always in good shape. I know my boyfriends always lusted after her, some even told me. One liked to look at her pictures while I went down on him. He had a foot fetish and used to sneak pictures of her feet and liked to show me after her visit (she is a size 6, I'm a size 10 and he always liked smaller feet).

I always acted like I was reluctant, but I confess that eventually being degraded, compared with my sister like that turned me on. I liked it when my boyfriend said her name when he came while I was blowing him or he was fucking me.