Hey, thanks for the advice here. She actually hates her husband right now and has admitted if it was possible she wouldn't of married him but now she is 'bound to him'.
Oh you should of said, this is EASY...
Ok get yer hands on a pair of woman's panties, SMALL ONES ! Huge Bridget Jone's knickers wont work for this... and don't nick them from someones washing line or you'll end up on the sexual offenders list and knowing you you'll tell the police i told you to do it as well.
Ok now you have to mess the panties up, I'm not gonna go into details here, use yer imagination and forget everything the youth book said lol
Now be a bit cunning and plant them either in the pocket of a pair of his trousers that your mums gonna wash or for maximum effect plant them in his book bag just before a meeting, preferably in the pages of his bible. When your mum catches sight of these soiled panties she will flip, trust me on this alright lol . And viola one huge crack in their marriage !
Remember all is fair in love and war
(takes tongue out of cheek)