Names changed so this isn't too outing.
A good friend of mine, Laura, invited me and one of her other friends, Gemma, (who I've met a few times before) out for the day with the kids.
We were chatting about allsorts and Laura went off somewhere with her dc. While she was gone, me and Gemma were chatting and the topic changed to Laura's husband. To cut a long story short, this man is a bit (lot) of an arse and has treated Laura badly in the past. Gemma and I were discussing that we didn't trust him, and that Laura could do so much better because she's lovely and the complete opposite of him. He works away a lot and Gemma speculated that he might be cheating and I said 'well it wouldn't be the first time would it?' - assuming that Laura had already told her as they're good friends. She had no idea and now I've betrayed Laura by opening my big mouth.
I feel awful and now I'm worried that Gemma will mention it to Laura and she'll be upset with me. What can I do to make this right if anything? 