Yes, the sperm die very quickly, almost as soon as they hit the air. But, in case, wash you hand quickly, and just don't ejaculate in your uw either.
No, this does not lead to pregnancy from what you've described. However if you're going to start doing this kind of stuff you're better off wearing a condom just in case you get carried away and end up doing more than that. At least you'll know you're protected.
More rubbed than fingered, but it was in the vagina either way