Yes, this is possible, but complicated to keep track of.
(link: "You say a mild hello.")[(set: $friendship to it + 1)(goto: "Acquaintances")] (link: "You spit in their face.")[(set: $friendship to it - 9)(goto: "Sworn Enemies")]
Oh, and it works the other way around, too.
"Can I come to the party with you?" you ask. (if: $friendship >= 50)["Sure, we'd love to have you."] (else-if: $friendship < 50)["Sorry, I'd rather drink acid."]