A short script and a handful of honest answers, for the moment you want to bring your partner properly into this — practical, not patronising.
"I've been doing some work on our fertility together — food, environment, some of the stress side of things. I've learned that about half of fertility is about male biology, and that sperm takes around two to three months to fully regenerate. That means what you do over the next few months genuinely matters. I'm not asking you to overhaul everything — just to look at one guide with me and see what feels doable. Would you read it with me this week?"