One option might have been to try to split up right after the pool game - establish that they're down for anything, then say you know your buddy doesn't like X (say hiking) but you really feel like X (paraphrased, say taking a walk outside).
Trouble there is how you'd handle any resistance from her friend (also assuming your wingman isn't a total dunce). Yes ladder might work.
Trouble there is how you'd handle any resistance from her friend (also assuming your wingman isn't a total dunce). Yes ladder might work.