I…don’t know that it would make much sense or fit into the dozen episodes we have left, I mean that’s talking about a whole character being introduced and starting a relationship in like half a season, and Nick being jealous would seem…weird.
He’s always treated Trubel kind of like a younger sister, so his being jealous of her new love interest would kind of squick me out a little. And I mean, too, the guy has enough to deal with already without preoccupying himself with who Trubel dates.
Also, I personally have always read Trubel as queer so if a hot Grimm did show up, no reason it has to be a guy. 😉