You say your boss is a good guy, if that is the case surely he would not mind modifying his behavior to stop the offending behavior. On the other hand, maybe he is not such a good guy after all, in which case you had better consult with an employment law attorney on how best proceed in your case.
Well, the one thing you failed to mention is: Did you ever ask him to stop? I'm guessing not. Sit down with him one on one and tell him that his lewd jokes are not funny to you and that they upset you. Ask him to not do it in front of you any more. Then you will find out for sure whether he is a nice guy.
Personally, I cast my vote that he is doing this BECAUSE he sees that it embarrasses you and makes you uncomfortable. Sounds like a sexual sadist, and since his wife is apparently totally in accord with it, one does not know WHAT to guess about her.
From here, the forecast is for scattered harassment and increasing stormy weather. Might be a good time to start seeking sunnier climates on the QT. Then when you lay your hand down, you won't be bluffing. I've got to work on this excessive mixing of metaphors. Good luck.
If you have already asked him to stop and told him how it makes you feel, then you may need to put in writing. This could, however, make him suspect that you may have legal motives on your mind. But if you cannot continue working in this hostile environment, you may need to do it, even if it means he may eventually become afraid of you and look for ways to end your employment. If you mysteriously begin getting bogus "write ups" after putting your complaint in writing, then you may choose to protest, in writing, the bogus write ups as unlawful retaliation. The links below may offer additional information on the laws which protect workers from harassment and retaliation in California.