oh and the step sibling thing is basically them "hating" each other and getting on each other's nerves for years. her mother had a string of relationships after her dad died and one of them (the longest) would've been with his dad. they never got married, but did get engaged and lived together for years. during that time these two would forced into playing family. it started off with some animosity, but grew into playful annoyance. even though they weren't technically step siblings, they had that dynamic for a long time and her mother was a strong mother figure (and still could be) for him and vice versa for lissa with his dad