Neither of them mentions being concerned about this at all. Their dialogue makes it clear it's a matter of them not quite knowing what they want out of their relationship now that they've begun seeing each other.
Also, Spock's and T'Pring's relationship fell apart because Spock and T'Pring are ultimately not compatible life partners -- Spock doesn't trust her the way he should, and he can't really help that. It wasn't actually about Christine.
I would hope that in the future, people have evolved beyond perpetuating misogynistic tropes like "home wrecker."
Charming.