The pair's outing comes just weeks after Brandon came out and revealed he identifies as a part of the LGBT (Lesbian, Gay, Bisexual and Transgender) community.
Speaking about the recent same-sex marriage vote in Australia, the actor wrote: "Just saw the "vote no" message in the sky, looming over Sydney.
The Radio 2 star responded to a Twitter follower's words of comfort as she comes to terms with her devastating loss. Love xxx.'While Zoe has been keeping a low profile since Billy's body was found in his flat in Putney, south-west London, she returned to the micro-blogging site to thank the BBC for airing the documentary Life After Suicide.
When the well-wisher told Zoe that she 'must be sad, bewildered and wondering what the point is', the broadcaster confirmed: 'Pretty much spot on. It has been reported that Zoe had asked a friend to check on her boyfriend because he stopped answering his phone, hours before he was found dead at his home.
A source told the Sun: 'Billy suffered from depression but the strain of being left with an unexpected tax bill hit him hard.'These sorts of things are a considerable concern for anyone — but it's particularly tough when someone already has mental health issues to overcome.'It is not yet clear what forced him to commit suicide - but sources say he suffered both his financial problems and mental health difficulties, as Zoe followed Depression Awareness and Anxiety UK on Twitter.
Thank you for raising money and hiring on a plane to write your lack of support amongst the clouds.
"I hope your hate and lack of understanding fades, just like those words will." Sam Smith is a 25-year-old London-born singer-songwriter, now based in the States.
He is best known for his role as Justin Foley in the hit Netflix series 13 Reasons Why.
He has also had roles in Home Movies and Brain Dead.
The BBC radio DJ became anxious when Billy's phone kept ringing out earlier this month - so raised the alarm to a friend, who then found him dead at his flat in Putney.