Idk. I was afraid to answer. I thought you might have been my wife. Lol.
It isn't because you are fat. A guy will be perfectly happy having sex with a fat woman that he loves.
I thought that it was my technique or lack of it when the wife gave up sex. But after lots of study on my part, she had no interest in learning or helping, I determined that she just didn't like the male body. At least mine. I tried to bargain with her. She didn't need to actually have sex, no fucking or sucking, if she would just help me masturbate. But no. It actually took too much work.
Which bring us to lazy. You know that you don't actually have to do much. Just lay there and spread your legs. I bet that you could sleep through it and he would be happy. Lazy is just a cover story for not wanting to make the guy happy.
I have determined that my wife really hates me.