Almost every love story has a supporting cast — friends, relatives, therapists, and others who play a key role in what happens. In Season 9 of Love Letters, we pay tribute to those important figures in the background. You’ll hear all kinds of stories about help and guidance people received in their romantic lives, from an ex who became the perfect wingperson, to the communities that support the spouses of pro athletes, to the best queer mentor anyone could ask for. Season 9 launches Jan. 23. Email us at loveletters@boston.com.