According to People's source, "things have felt super heavy in the relationship for a while, and it got to be too much," which is why they have allegedly broke up.
E! News also reports that the breakup was "very messy," but because they are on the same television show together, things needed to be handled carefully. "They’re both very professional though and trying to be as amicable and friendly as possible," says the source.
But it's not all bad news. Their initial split may have actually happened a while ago, and now, they could be on the road to recovery.
"It seems they could be heading back in the direction of getting together," the source said.
Sources confirmed earlier this week that somebody overheard Cole talking about the break up to a friend at a Comic-Con party in San Diego over the weekend, Us Weekly reports.
Cole and Lili were attending the Comic-Con event together to promote Riverdale.
Hopefully, they can work out their differences, especially for any upcoming seasons of Riverdale.
However, it does not seem likely - not for Betty and Jughead.
Cole and Lili, (who are currently filming season four) revealed to Entertainment Tonight at Comic-Con in San Diego that Betty and Jughead will face major issues as Jughead leaves for another school.
We all know that long-distance relationships can be very trying and it's a topic that will come to the forefront in the hit Netflix show.
Cole told ET that his fan-favourite character will head off to prep school and will be "only back in Riverdale on the weekends."
Adding to our fears, Lili added the "distance will probably cause some stress."
But, Cole isn't worried about the pair's future as a couple.
"I think it might be a little bit tense. They might fall, turn away from each other, only to come back together way stronger. I think they're gonna be really good" said the Five Feet Apart actor.
WATCH: Lili Reinhart and Cole Sprouse arguing at Comic-Con proves they aren't together