Responses
In the omegaverse hyesung the mom is its maternal instinct..and seems like it's heat...tho he's hearing crying noises which is wierd.
To me it feels like he got some crazy connection with his son, being able to hear his cries and the crying makes his body react and releasing pheromones so he can be located.
Little detail, but Dojin dressed up "Comet" Hyesung in comet/space themed pyjamas and he dressed up "Star" Byeol in star patterned baby grows, thus matching their clothes to their names.
Guessing Hyesung has went into heat or his paternal instinct has kicked in which might alert Dojin...