[intuition897]

Bud, it sounds like you and Su are one of those lucky couples who have managed to successfully swing with a close friend. Not many are willing or able to do that, because you risk things "getting weird", or losing your friend should anyone overstep the personal emotional space boundary of your relationship.

It sounds like that first reaction was in the normal range. It's probably a good thing to worry about, whether you're doing the right thing or not. But if you really can't see any clouds on the horizon in this situation, you really don't see it endangering your relationships with one another, then why create clouds where there are none? You sound like you're well adjusted to the idea of swinging, so that's great. I'd just suggest that you follow up with Su, get behind that smile and find out if this is actually what she wants or if she just feels like it is somehow expected of her? This is an opportunity to deepen emotional intimacy with one another. Don't settle for the "Nothing's wrong, dear" answer if you are sure that there's more to the story.