Fans watched on in horror last week as Janet Mitchell (played by Grace) was mown down by a distracted Tina (Luisa Bradshaw-White).
Billy (Perry Fenwick) was kicked out his family home by wife Honey (Emma Barton) following an explosive hospital bust-up as the pair struggled to cope.
Tina is weighed down by guilt for accidentally knocking over Janet, and does her best to support Billy who is unaware of her actions.
With both of them in pieces and needing support, he leans in for a kiss which Tina reciprocates.
The new Walford romance will go even deeper later in the week as, desperate to help him, Tina invites him into the Queen Vic to try and console him, but ends up jumping into bed with him instead.
As they awake the next morning, Tina is riddled with guilt.
She confesses all to Billy before he makes a desperate dash to Walford General to win back Honey.
Will Billy reveal the identity of Janet’s hit-and-run driver?
Tina later tells Shirley Carter (Linda Henry) that she revealed the truth to Billy and will hand herself into the police alongside him.
However, she stops the pair in their tracks – what could possibly go wrong? Could Tina use their affair to silence Billy?
EastEnders continues tomorrow on BBC One at 8pm.