None of my sisters are hot enough that I could ignore the socially ingrained taboo of incest, the guys who want to fuck their family members usually have the hottest family members, you ever see those guys that have awkward relationships with their mom's, ever notice their mom's are hot milfs, that's not a coincidence
In order for your mind to ignore years of indoctrination to have an aversion to incest and be repulsed by it, said family member has to be proportionally attractive relative to the level of indoctrination or more, they have to be very attractive, I have no family members that are that attractive so I've never had such thoughts
But I've seen guys with sisters that have ridiculous bodies and I'd make jokes and they'd take long to respond, and I could tell it crossed their mind before, people can pretend all they want, but tits and ass are tits and ass, if the average man was walked blind folded into a room and told to fuck another blind folded woman in a room, he would be erect just by touching her body, he'd only lose said erection if it was revealed to be a family member, its psychological, socially ingrained into you, but if said family member is very attractive you aren't going to care much, because your desire to fuck will exceed your socially programming
