Tom had a choice.
He was angry, and felt rejected by B'Elanna, so with 4 gallons of spite pumping through his heart he asked Seven of Nine on a date with every intention of hatefucking her as publically as possible so that that Klingon *&^^% would know what a good thing she was missing out on.
In her broken condition, there's no way that Seven wouldn't have imprinted on Tom.
10 seconds after asking that drone on a date, B'Elanna reaffirms her loving feelings for Tom and demands that he not be such a dick who would run away from his feelings for her too.
Anika is forgotten about.
Maybe this is why she fluffed harry in the mess?
Any way, Tom's part in the Seven of Nine Show, as Voyager became in all but name, would have been Rikki, rather than Fred Mertz, if he just would have taken that blonde out for that date she had ccepted, and lived happily ever after