The more Felicity (Emily Bett Rickards) becomes like Oliver (Stephen Amell) on Arrow, the more complicated the former couple's relationship gets. And that tension will all come to a head in an upcoming episode when the pair finally hash out their many issues with each other.

"They've had some issues that have been bubbling underneath the surface. They haven't even really been bubbling. They've been beneath the surface," Amell tells "And we find out why they're beneath the surface, that there's a very specific reason that we delve into."

The current strain on Oliver and Felicity's relationship — which centers around her involvement with Helix — will also bring up some long buried feelings the pair has about issues outside of the clandestine hacker group. "Them being head-to-head in terms of one having a differing tactical opinion than the other one brings some of their more personal opinions back to the surface," Amell teases.

Arrow airs Wednesdays at 8/7c on the CW.

(Full disclosure: is owned by CBS, one of the CW's parent companies.)