You speak to her quietly beforehand, explain how you feel. She probably knows what you mean, and feels all guilty and embarrassed when he behaves like that. She probably understands and would welcome you setting him straight and speaking your mind.
Or, she'd at lest know if it would cause trouble and have recommendations...

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You know, Blackadder, for me socks are like sex. Tons of it about and I never seem to get any.

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