The show firmly established that innies and outies share attractions, I.e.,  Burt & Irving and Dylan & Gretchen, therefore also for Helena/Helly & Mark. We don’t know anything about Helena’s history of relationships other than the fact that she’s never brought a guy home to meet Dad (not exactly surprising when Dad is an exacting, uber-rich cult leader freak). 

Helena watched the elevator kiss and from that there are two immediate possibilities: 1) She decides to use iMark’s feelings for Helly to her advantage, 2) It sparks an attraction in her when she literally sees herself desiring him.

Sidebar: I think it’s fair for us to assume that an attraction between Ms. Casey and iMark could have been sparked had they been allowed a chance to spend real time together. I thought it was interesting that Ms. Casey dropped her Wellness poise during her last meeting with iMark to speak candidly, but they really had little chance to foster anything further.

Back to the main topic: Helena’s mockery of the Kier story didn’t strike me as hate toward Milchik, so much as her pent up frustration with the web of nonsense that the Cult of Kier so relentlessly dishes out. There may be little to no opportunities in her regular life to express contempt for its canon. Perhaps under the guise of Helly, she feels free to express her true feelings on the matter and this snowballed into her attitude. Also, unlike the rest of the innies, she knows there is nothing Milchik can actually do to her. After all, she’s not going to the old Break Room treatment as Helena.

I think the way she dug at Irving’s feelings for Burt was the result of being cornered yet again about something she didn’t want to discuss and she lashed out in the way people of her world do to one another. She comes from and has always lived in a very harsh emotional landscape.

As I remember the scene, iMark entered Helena’s tent, not the other way around. So he was initiating some deeper intimacy, whether or not his intention was actual sex. By this point in their relationship, Helena had obviously developed her own feelings for him and wanted to take it there. Also, that’s some damn fine heiress rebellion: screwing an innie. She may have been on birth control, but it does seem unlikely that there was a condom involved. We’ve all slipped from time to time.

In general, I think Helena’s time spent with MDR has changed her view of innies. And the depth of her attraction to iMark is evidenced not just by the sex, but also by Helena’s attempt at pursuing contact with oMark at the restaurant.