The showrunner said that although a reconciliation between Robin (Cobie Smulders) and Ted (Josh Radnor) is "always on the table", the former must also deal with "lingering" feelings for her other ex in the group.
"It's a love triangle. As long as they're all in each other's worlds, there's always going to be that tension between these three characters," he told TV Line. "It'll take something big happening for that to go away."
Last month, a How I Met Your Mother star revealed that she is "a very good contender" for Barney's (Neil Patrick Harris) mystery bride.
Bays has promised that her identity will be revealed in a May episode, adding that the show will continue as a "delicate dance between lighthearted comedy and real issues".
How I Met Your Mother airs in the US Mondays at 8/7c on CBS. UK Viewers can catch the latest season Thursdays at 9pm on E4.
> 'How I Met Your Mother' exec: 'Show could continue past mother reveal'