I love the idea of them having twins cause one of them decides to become vegan while the other is hyperfixed on insects throughout his childhood. Parenthood is hard for both of them; Rui has to run behind his pup so he won't take any insect inside their home and also keep Tsukasa safe by getting the bugs out when he hears Tsukasa screaming in panic over the smallest caterpillars. The day the tarantula accident happens Rui is busy in his home workshop in the basement when he hears a loud scream followed by something hitting the floor and then his child crying so loud, of course he gets scared. It's just that, a big scare. Tsukasa wakes up just fine, but his puppy is so scared he hurt his mama, he still hugs Rui so hard when apologizing to his mommy... Tsukasa says it's fine when Rui moves their little pup from his arms' to Tsukasa legs, but the omega asks him to please not do it again since he gets so scared.

From then on, he gets his insects' knowledge from the books Rui gets him or the documentaries they watch together. Tsukasa can't watch any of those, but he is happy at least his papa can be more supportive of his love for those tiny (and creepy) creatures.