This is obviously an area that requires 100% unequivocal consent, that is revokable at any time. It also requires communication. The OP says it makes him uncomfortable, so why do it? If you do choose to, then communicate clearly, and ask her to tell you what feels good. Of course if you aren’t comfortable doing it, stop.
As you can see it’s a reasonably common kink. And as stated above, there have been some high profile celeb deaths too (what an undignified way to go, naked, ligature around your neck and your dick in your hand!). Who knows how / why it feels good. I’m not a fan of the whole idea, tho one girl I’ve seen a number of times has asked me to at least put my hand around her neck . I always figured she was asking because she thought it would turn me on. (Not really my thing, but she seemed to like)
The other thing to consider, is if things go wrong, some freak accident happens (rarely compressing the carotid can rarely cause
A stroke, and a general lack of oxygen to the brain can trigger other bad stuff) and she gets hurt or worse, that would be a disaster.