You can explain that you were exploring your own body in a different way, and it wasn't because of any dissatisfaction in your relationship with her. Say that you understand it made her uncomfortable and that you'll be more discreet in the future.
Well, first of all, it's an extremely awkward situation. You should probably be honest with her about why you were using it. Maybe it was just an experiment or something you were curious about. Try to have an open conversation without getting defensive.
Well, first of all, try to stay calm. It's important to remember that a vibrator is just a tool for sexual pleasure. Maybe start a conversation with her in a non - judgmental way. Ask her about her needs and desires that she might not have been expressing. For example, you could say 'I noticed you had a vibrator. I want to understand if there's something I can do differently in our relationship to make you feel more satisfied.'
It's extremely normal. Using a vibrator doesn't imply any dissatisfaction in the relationship. In fact, it can be a sign that she is in tune with her sexual needs. There are various reasons she might use it, such as relieving stress or just having some personal time to relax and enjoy herself. So don't worry too much about it being abnormal. Just approach the situation with an open mind.
First, try to stay calm. It's important not to overreact immediately. You could start a conversation with her in a non - judgmental way. Ask her about her feelings and needs. Maybe she has some unmet sexual needs or she just wanted to explore something new on her own. Communication is key here.
One way to react positively is to show understanding. If she made a mistake out of impulse, tell her it's okay and that everyone makes mistakes. For example, if she accidentally spilled coffee on your important papers, instead of getting angry, you can say 'It's just papers, no big deal'.
You could start by simply stating the truth. If it was for a fun event like a costume party, just say that. For example, 'We were getting ready for a costume party and this was our creative take on it.'
Tell her it's a form of creativity. You might say that just like people experiment with different hairstyles or clothing styles, crossdressing is your way of being creative with your appearance. Give her examples of famous artists or performers who crossdress as part of their art.
However, if by 'naughty' you mean she did something that might have upset you like breaking a small promise, it's important to communicate. Sit down with her and calmly explain how her action made you feel. Maybe she didn't realize the impact of what she did. For instance, if she promised to cook dinner and didn't, but instead went out with friends, talk about how you were looking forward to that meal and how disappointed you were.
We should focus on positive, healthy and respectful relationships in communication, not such inappropriate scenarios.
Just be straightforward. Sit her down in a calm environment and say something like 'I know you've been cheating'. Avoid yelling or accusing right away. Let her have a chance to explain herself.