I fear that I might end up speaking out, as they have now started making up too many stories and excuses.

There is a poignant tension here between holding one's tongue and letting the raw truth spill out. The lover has deliberately kept silent to protect the dignity of the beloved, but as the beloved spins more and more excuses and fabrications, that patience begins to fray. The fear is not born of anger, but of sorrow—because if the speaker finally speaks, the illusion will shatter and secrets best kept safe will be laid bare.