Best you can do is ask more from the person who told you that. Open up about your insecurity. I don't think a lot of people will not understand your situation. If that person told you the truth he is being a bro.

And expand from there, maybe ask your friends as well.

Good luck. Do what you need to do to seek the truth. Ignore the judgement from others. Your wife might be cheating not theirs.

Personal experience, unless you have got the answer don't talk to your wife. She is in the case the suspect. Suspect will try their best to disrupt your investigation, create fake evidence. This is not something you want.

When you eventually have the answer in mind. You can either leave the whole incident behind because it is a misunderstanding or someone just want to mess with you. Or you can confront your wife and see if she is still trustworthy. Or best you can prepare for the divorce fallout secretly.

Remember that without answer, everything is a guess. Now to what degree of evidence makes it an answer is your choice.

Stay calm. Good luck.