okay. they'd have ended up dying anyway. at least in this case we still get to have a full lifetime of friendship, while if I chose them, yeah they'd get to live forever, but I'd die sooner
and more questions
what do you mean by friend? because if partners aren't included and it just goes straight to regular friendships then that's not even that big of an issue anyway
and what does half your lifetime mean? are we assuming that we're all destined to die at a specific time, and then when this happens it just gets halved? because in that case, let's say I was destined to die two years from now in a car accident, wouldn't I die as soon as I decided to make my friend immortal, since I'd have already passed that middle point?
A partner is considered a friend
Half of your natural life (meaning when you would die of old age)