I am totally in love with her but why nowadays why I imagine of being like a child or baby to her......?

though she is younger to me but she is wiser than me and she too truly loves me. I imagine on dancing her one's finger, I imagine her to hold me when I fall, I imagine her to carry me on her two hands for a while and such. On sms I have started sometimes calling her mamma, baba(daddy), didi/didu(elder sister), dada(elder brother) and she feels happy and emotionful with it.