analyzing my kink

so i'm this mommy type thing for my partner and we play lots of little girl scenes but lately i've been really into roleplaying as an older sister too like the big sis who knows everything but also gets kinda harsh with lectures when they screw up it's all super hot though cuz he loves being scolded and then comforted afterwards i'm curious if this is just a phase or if there's something deeper here about why older sister figures are such a turn on for me does anyone have any thoughts? lol