Hi Peggy,
What a fun limerick! I hope we never have to go to LJ!

My only nit is you closing line: it seems to be missing a beat and isn't quite as smooth to the ear as the rest of the poem:
Bawdy humor is their functionIt's also your choice of the word 'Bawdy' - dum dum - combined with humor. The two words are opposing each other in the metrical category here.
Perhaps this might work as an alternate:
lecherous
or maybe swap humor with tomfoolery : lewd tomfoolery is their function.
Cheers
~Cleo