If you saw GotG Vol 2 recently, romance wasn't a central part of that movie either, but it was still there. There was no big kiss at the end sealing the deal, but there was a line that more less serves as an admission of reciprocal feelings between the characters in question. It might take them another movie to really go full canon, but it's pretty much inevitable at this point.
This would make a pretty good comparison. Slow burns are better especially between two people who started out at odds together, like Gamora and Star Lord but the seeds are there. All it needs is a bit of time.