My wife found a lover on the internet, and that person sent me a text message saying that she loved her. What should I do?

Take a short message and ask your wife who this person is in a relaxed tone to see her reaction. If she says it's just for fun, tell her that you believe she won't betray her family, but it's hard for you to do so. Ask her to put herself in others' shoes. Will another woman be angry if you contact her like this?

If she admits that they cheated, quarrels with you angrily, or cries for forgiveness, then the decision is up to you. Whether to go or stay depends on whether you can accept this reality.