If you best friend had more in common and connected more with your partner, would it be a problem for them to date? Now a lot of people have rules of girl code or bro code but if you can clearly see that your best friend and your partner are a better match than you and your partner, surely you should be happy for both of them. Yes you are the sacrifice and may lose one of them, if not both, in the process but you should want the best for your best friend. It can be argued that nobody should separate nest friends but true friendship overcomes the hardest of obstacles. Is it OK or not?