BEST FRIEND OR NEW LOVER ?

I’m writing an urban romance book and I’m having trouble deciding if I want the two best friends to date.

The entire friend group (2 girls and 1 boy ) has known each other since grade school and have always been close like literally brother sister close.

The main friend that I am writing about already has a man. But I can’t decide if I want to make the other two friends date or fall in love with different people. If they date it’ll change the line of my story and if they see other people there’s underlying chemistry that I didn’t mean to write in but somehow flow naturally.