monchele29
What if Kara and Oliver were in a secret relationship and didn't tell anyone on their teams?
Kara was dealing with a lot after she sent Mon-El away to keep him from dying of lead poisoning. After she agreed with her sister about spending time away from both her jobs as Supergirl and Kara Danvers.
She runs into Oliver by accident and she discusses that she needed time away because of Mon-El after sending him away from the lead poisoning that Lena sent up in the air. Oliver was on the same page after him and Felicity split up with him again.
Oliver agreed to have Kara stay with him for a couple of weeks until she was ready to get back out there and be the woman that everyone knows and loves. They just didn't expect that they would fall in love with each other during her time spent on his Earth and in his city.