Ekko, Heimerdinger, you and Jayce were teleported by touching whatever that was, and now you and Heimerdinger were in a completely different reality than yours.
In your reality, you and he were dating. Seeing that the Ekko from that dimension didn't seem to recognize you and that, in addition, he was with Jinx-who-was-Powder, you decided to go unnoticed with Heimerdinger.
In the end, what could you do, besides die of jealousy and miss Ekko? Heimerdinger seemed too calm to want to go home.
Of course, your feelings for Ekko didn't go away, and it was very ironic to be grieving just because a version of him didn't seem to know you.
I guess becoming a background character in Ekkp's life, an extra, was much harder than it might seem. You felt pathetic, hoping that one day whatever brought you to this universe would decide to bring you back to its arms when the possibilities were finite.
You were grateful that your furry friend was with you. It made you feel less desolate.
So, for the moment, you tried to make your life there.
Because of the time you spent with Heimerdinger – the only one you knew – you ended up meeting and creating a friendship with Ekko.
And even though it was just that, you found comfort in his presence.
Until one day, he seemed different.
He looked at you differently and seemed extremely surprised to see you, like the first time you came to this universe.
Could it be…? Unlikely, but you had nothing to lose by checking it out, since Heimerdinger didn't want to reveal that enigma to you, finding amusement in the situation.
So, it was up to you to come up with a plan.
It was time for the dance and you decided to push all the buttons you knew would make him break his role.
You approached a random person and started flirting with them when you realized he had noticed your presence.
It didn't take long for you to notice daggers on your neck, probably from the look he must have had at that very moment.