Measure For Pleasure at The Public Theatre is very funny, ribald and bawdy. Right now it is in preview, but opens soon.
Nota bene: if this friend of yours is easily embarrassed by sexual innuendo (and out the other--sorry) and double and triple entendres, then this may not be for them. It isn't 'dirty' per se, but it is chock full of, shall we say, hijinks and not for the prudish.
However the 70+ year old couple who were sitting next to me last Sunday afternoon had as grand a time as I did.
"If my life weren't funny, it would just be true. And that would be unacceptable."
--Carrie Fisher