Boy,Miguel,you are confused. I think you're the problem here, not your wife. First of all, you should not have lied to her about seeing Diane.You should have telling her the truth. There are a few of the reasons that have shown what have you done,and what should you have done.

Firstly, You and Diane are just friends. There is nothing to hide.Why do you lie on your wife to seeing Diane? It might have made things worse. You have got to be honest to your wife.You should have asked your wife to have lunch together with Diane as well. Secondly, you do not respect your wife since you lied her.You must have to respect other independence,freedom and lovable,and your wife should have to know it too. Both of you need to communicate with each other to avoid misunderstanding. That was not a big deal to meet Diane. To maintain a good relationship between you and your wife, you should have to know about sharing too. Share your happiness and sadness,it will also make your relationship to hold together. Do not blame on your wife of jealousy. It could be happened on every woman as they do care about their husbands.You should have learned to be forgiving. You should have tried to speak whisper to your wife, It can also be worked.The most important thing is, both of you should have to give some spaces to each other. Support your spouse even if you can't support the issue.

You must learn to listen your spouse, respect him or her,give what your spouse want and not what you want of your spouse. Do not do whatever you do not like somebody does to you. It might take both spouse time and effort to work together to maintain a good relationship, do not give up the relationship because of minor problems.