1 Corinthians 7:12–16: Desertion and Divorce
First Corinthians 7:12–16 speaks to a believer married to an unbeliever who is content to stay, and to desertion by an unbelieving spouse. It gives no procedure for divorcing someone in prison, so the deciding question is who is leaving and whether the unbeliever is willing to remain.
2 Corinthians 6:14–15: Dating Apps and Unequal Yokes
Paul does not mention dating apps, but he does address the bond a believer forms with someone who does not share faith in Christ. The question is less about the technology than about the yoke a relationship becomes.
2 Corinthians 6:14 and Dating an Unbeliever
Paul never uses the word dating, and he does not call it a sin. But he does warn that a believer's closest attachments carry spiritual weight, and dating an unbeliever is the kind of unequal binding he has in view.