Three Months???

The ending/reboot aside, I think it was worth mentioning in the first movie that Mack and Brady only even met three months ago (unless it wasn't supposed to be that way starting out?). So how long does that mean they've been dating? Two months? One? In TBM I was under the impression that they'd at least been friends for years and had maybe been dating for 5+ months or something. It just gave everything a weird feel for me because we're supposed to care about them as a couple yet they've only known each other since summer started.