I'm a bit stumbled on the meaning of で踏めるな here.
So the character sister's gets home and she's shocked her brother brought a friend. Then the brother introduces the friend and the sister goes "nice to meet you, is the curry good?" and they answer "we still haven't eaten yet"
After that the mother adds
"で踏めるな" The part before the で are the protagonist and the brother's names.
to which the sister replies
踏んでどうする
The protagonist too seems to be confused to I guess it may be a weird meaning?