I just returned from the party.
The stripper thing turned out to be a non-issue, as apparently he cancelled. I'm not sure when that took place; presumably sometime later this week. Birthday girl did have some inkling apparently. There was mention of a different stripper coming at 10.30pm instead, but I think that was a joke, or at least not actually going ahead. I only got this info from overhearing the organiser telling someone sitting close to me.
The whole party was fairly low key and DH, DS and I were the only "inlaws" there, and the only other person we really knew was a mutual friend of birthday girl and myself, and she left just before we did (at 8.50pm to pick up DS1 from work).