Let's say you're 20+. And you have a sister who's 18.
You and your sister are born again christians.
Your sister gets a boyfriend.
The boyfriend is Catholic.
Your sister dates him.
You don't want your sister to have sex.
After 5 months, your sister and boyfriend have sex together.
Your sister's boyfriend doesn't know what you want.
They both start doing kinky things; the boyfriend goes down on your sister, vice versa.
The boyfriend is madly in love with your sister.
Your sister is madly in love with her boyfriend.
They break up after 10 months.
Your sister tells your boyfriend that if he gets the blessing of her sister, then they'll get back together.
Is there any possible way of you giving the boyfriend your blessing?