erthromycin:

Erythromycin is an antibiotic used for the treatment of a number of bacterial infections. This includes respiratory tract infections, skin infections, chlamydia infections, pelvic inflammatory disease, and syphilis. It may also be used during pregnancy to prevent Group B streptococcal infection in the newborn, and to improve delayed stomach emptying. It can be given intravenously and by mouth.

Uhhhh....

Kind of an odd thing to be in an autocorrect dictionary...

Anyway, I think he's trying to say that his wife had a very sexually (and just generally) traumatic childhood, sometime now into their marriage, after they had previously done several threesomes, she is now simultaneously saying "I am asexual but I don't expect you to be" and also "Don't sleep with people in our town."

So... I guess she is saying that he would need to go far out of town to have sex, that would be ok with her?

???

Either way, none of this really describes "what's keeping him in" or how/why he's handling it.