In reply to stonemaster: In my experience begging permission from her indoors is always doomed to failure. Much better to approach such a daunting task with a positive message such as.
"Darling I have found a new way to lose some weight and it really is guaranteed to work"
or
"Darling remember last week when you told me to F-- Off and lose myself? Well "
or
" Darling you know when we were in Spain on holiday and you said I looked great with a suntan? Well"
If all fails then yes resort to begging although bribing normally also works.