Is it evil to do this

My bf has had at least 3 sexual partners before me and he says he “knows” he doesn’t have an std but he’s never been tested. I’ve told him so many times you can have one without knowing and he just refuses to get tested. I saw this thing that you can send someone an anonymous message like this:

I thought it might scare him into getting tested but also makes me kinda feel evil. what do you think and don’t hate on me I’m just concerned he has no knowledge on stds he thinks he’s completely safe because he’s never had a full on herpes outbreak before