We are preparing for marriage

My significant other treats me very well, but isn’t born again in the Lord yet. Also, pray if there are any weaknesses in the flesh that would be damaging to our marriage that those will be resolved prior to the marriage. Pray the marriage wouldn’t have sexual infidelity/adultery and be protected from that. I get scared of what my significant other may be doing on the mobile phone, and it causes me to question the loyalty of my partner in the sexual sense. I seriously hope my significant other isn’t having sexual relations with anyone else, because I’m not, and I would appreciate that same kind of loyalty. I enjoy our relationship together, and want true intimacy long after the wedding day, so I appreciate any prayers over this.