In the case of "alienation of affection" would BC be responsible for child support and alimony? I am assuming alienation of affection can occur if one side of the marriage decides it will become a sex-less marriage.
No, alienation of affection is a lawsuit one spouse files against the girlfriend/boyfriend of the other spouse. Mr. & Mrs. Less are married. Mr. Less begins an affair with Miss Hot Pants and Miss Hot Pants knows that Mr. Less is a happily married man (probably with children, but doesn't have to be) and Mr. Less decides to separate from Mrs. Less. Mrs. Less has proof of the affair and she sues Little Miss Hot Pants for alienating the affection of Mr. Less for her. Mr. Less isn't sued. Little Miss Hot Pants is. Little Miss Hot Pants, if she loses the lawsuit - and most of the time she does - would have a judgement entered against her for whatever the damages are. There was a $500,000 settlement in Alamance County, NC a few years back. Mrs. Less then sits back and waits to collect on her judgement against Little Miss Hot Pants - who a lot of times has then become the 2nd Mrs. Less. Ex-Mrs. Less can then still be awarded alimony/child support from Mr. Less.
P.S. - And then, of course, is also the division of community property - where Mr. Less has to give up half of his house, cars, boats, money accounts, retirement, furniture, any and all assets that were gained during the marriage. All because Little Miss Hot Pants couldn't go out and find a single man - she'd rather take a married man away from his wife and family, cuz it's just so much fun!