Sentence:  Many people are involved in relationships in which they do not know how their <WSD>love interest</WSD> feels about them. ... They may also fear knowing the truth, which may be that their <WSD>love interest</WSD> isn't truly interested enough in them to make a commitment to the relationship. 
Meaning of the word marked with <WSD> tags:  Especially of a character in film or literature: one who is of interest as a (potential) partner in love.