Yup, yup, this pretty much confirms everything I already thought when she was describing her relationship with her shitty ex - she agreed to it after he "had been pursuing her for a long time", then she broke up with him because she felt like it just wasn't working out, it's really just that she grew up in such a heteronormative environment that she simply never figured out that it could work any other way.
With how sweet and innocent Tongtong is, I bet she figured that all of the romantic feelings she never had for any boy would simply come once she was in a relationship with one, not knowing that there was even a chance that she could not be into boys in general.