One key element was the class difference. Tyrion was a Lannister, a high - born in Westeros, while Shae was a prostitute from a lower class. This difference added both charm and challenges to their relationship. Another element was secrecy. They had to keep their relationship hidden, especially considering Tyrion's family and the society's norms.
Trust was an important aspect that was both built and broken in their love story. Initially, Tyrion trusted Shae completely, bringing her into his life and sharing his secrets. However, as the political situation worsened, Shae's trust in Tyrion wavered, and she ended up testifying against him in court, which was a heartbreaking turn of events for Tyrion.