You have to take the same precautions, whether you've been with someone for one night or six months. The sad reality is that people lie about these things, to themselves as much as each other. I don't think it's someone's place to tell anyone else to get tested. If you're going to do that, you'll let your defenses slip when the results come back negative, and that's where people get infected. Perhaps you're both perfectly virus-free.
Chances are, it's true.
But there's always the chance that you're wrong. Or that your partner has cheated, or you'll succumb to temptation. Keep it as safe as possible, is all I say. So to be asked by Fox to get tested, I figured he hadn't listened to me. Or worse, I was going through some set of conditions in order to be accepted by him.