the prpblem is shes only acting that way because shes freaking out about turning 30 soon. she doesnt actually find the man fun, interesting, or attractive. shes just pretending because of her desperation to have children.
if the man were to marry her, and pump some kids into her, sooner or later her mind would clear. The desperation googles would come off and she would realize how unnattracted to her husband she is. then comes the "i never really lived you speech" and a quick brutal divorce that leaves the man financially ruined, unable to see his kids, depressed and suicidal.
does that sound like a good future to you? to be used as a sperm donor and beta provider before being discarded so the mother can go fuck her boy friend in the house the man is still paying for?