Of the two ex-es...

....I think Dev will pose a greater danger than Sameera.

Because, Dev comes across as a thoroughly amoral human being who doesn't seem to acknowledge the fact that he's behaved badly. This and his unexpected attraction for Geet will cause more trouble for Maneet than Sameera's arrival.

Dev has already been unfaithful to Naintara in deed. Now he's unfaithful in thought as well. The fact that he's hiding the truth about Geet and him and about her presence in Delhi seems to indicate that he plans to pursue Geet once he finds her and when he learns about the pregnancy, he's somehow going to use it to his advantage....and oh boy! once he learns about his bro's feelings for Geet, that's it!.

On the other hand, Sameera, the Positive One's arrival may just be the thing that will prevent anything untoward happening...don't know how, tho!

I hope you are right Pippa and Sameera helps Maaneet instead of proving to be another hurdle. As things stand I can only expect the story to take a turn for the worse next week with Maaneet caught in the middle. I am still curious to know how Maan will react to Geet's pregnancy once he comes to know of it.

but it will be funny being Dev and Nt at loggerheads... perhaps both of them not knowing who is out smarting the other....

I can't think any negative scene anymore. I want MG be together even when they are in a critical moment.