Robert and Aaron subsequently got engaged after they were involved in a car accident involving many of the other villagers.
Robert and Chrissie's half-sister Rebecca slept together in 2017.
Robert initially decided to leave the village, not wanting his son to turn out like him, but a few home truths from Aaron changed his mind.
Robert returns Seb to Home Farm, where a distraught Rebecca accuses him of taking Seb, and reveals Robert's plans to take Home Farm from them.
A fuming Chrissie makes clear that she blames Robert for Lachlan's disappearance before throwing Robert out, telling him to never step foot in Home Farm again, before threatening to kill Robert if anything has happened to Lachlan.
Aaron later told Chrissie of his affair with Robert and Chrissie threw him out.
Robert refused to sign the divorce papers, so Chrissie set fire to his car, but much to their horror, this resulted in a massive explosion, sending a gas canister flying into the air and hitting a passing helicopter, which careered out of control and crashed through the roof of the village hall.