My sister kissed me?

She's my full blood sister, younger than me but less than a year (mom got pregnant again right after having me).

We have always been really close, so this is extra confusing for me.

After she did it she said she was embarrassed because all of her friends have kissed someone and she wanted to know what it's like, so she kissed *me* to find out.

I understand why she might have thought about it but she just did it without asking, I didn't have any option. How do I explain to her how she made me feel?

My sister kissed me?
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