And with her partner, it would have been extremely difficult: the slightest hint of doubt on his face or in his voice would have been devastating for her and would have probably meant the end of their relationship.
навряд ли со своим парнем... даже малейшая тень сомнения на его лице и в голосе стала бы для неё крахом, и, возможно,  привела бы к разрыву отношений.