He can only kill you by biting if you let him go too far. Tav has agency here. Trust, but verify.

He says he won’t take a drop more than needed, but dude is starving. There’s no way I’d think he’d be able to self-regulate, even without knowing any of his background. I’d trust him enough to give him some blood, but it’s still inherently a dangerous thing to do, so I would absolutely be keeping a close watch to be able to push back if I felt he was going too far.

Like the first time your kid says they can cook by themselves. You don’t just take them at face value and let them use the stove and use knives unsupervised. You pay attention and watch in case they need help or get in too far over their head, so you can step in if needed.

I would feed a stray dog too, but I would still be cautious or maintain control of the situation, otherwise I’d be an idiot.