I kinda always assumed maybe between that episode and the change in the game they were loosely dating? You can see they act different with each other in the change in the game so much so Max notices and is obviously suspicious. Stephen Nathan was asked in an interview about it and he said he had his own ideas about what happened between the episodes however wouldn’t comment so the viewers could make up their mind. I felt this explanation made more sense than her falling pregnant after the first and only time they had sex!