This might help...ring size is 6.5. She's a little loose but won't fly off. I am hoping that once we add the w band she'll snug up. I tried to explain to the Fiance about why it seems loose. He is concerned that it is too big. I showed him the set of stack rings I have that I wish were half a size bigger because when I wear them all together they are really snug and kind of uncomfortable but alone they are great. I can't remember what size they are, either 6.5 or 7...I think. I'll need to put them on one of those sizing bars to know for sure. He isn't convinced. Any ideas on how to snug her up without too much trouble?

I noticed that it looked slightly big, but some like to wear their rings a little loose. Since you mention you are going to stack bands with it, going a little loose is a good idea. For now, you could go with a plain thin, 1.5-2mm, discreet spacer band in front of it for security and snugness. You could even do it in rose gold, which either will blend with your skin and be almost unnoticeable, or match with your ring, depending on your skin tone.

Kind of like this one on PS., although hers is .75mm