Valentine's Day is the last hurrah for cuffing season. Cuffing season is now over.
The women who get cuffing season boyfriends in the late September - early November time frame tend to drop them either right after January 1 or right after Valentine's Day. Valentine's Day is only 6 weeks after January 1, so it's often worth keeping the guy around for another 6 weeks.
There will be many breakups in the next 2-3 weeks.
Additionally, a lot of longer term relationships break up between November - March. In marital relationships, divorce filings are most common in January - March. Non-marital relationships also experience a lot of breakups in the November - March period, but their pattens vary more as compared to marriages.