Is it normal that my sister keeps flashing me?

Whip ur dick and twirl it around like a fan and blow her out of the room then like a normal person

Do the same. Get it hard n walk around tent pole like. Bet u can get her to suck it! Sister pussy is good... Me n mine did it a lot when we were younger

your sister is obviously trying to get your sexual attention. its up to you really, if its something you want to do with her ie fooling around and she is the instigator you should go for it.

how old is she???

She wants u to put it in

Tell her to get the fuck out of your room.

she wants you to hit it

I've always been a bit of a flasher and for sure if this was happening to me she would be noticing my erection, and sometimes when she came in my room I would be wearing my baggy shorts with no underwear and she would be getting similar views of me, including the wet spot on the front of my pants or shorts.
I probably wouldn't have sex with my sister but we might end up masturbating for each other.

tell her to put it away as its disgusting

It's not a big deal. Just tell her to leave your room because you want to rub your nuts.

Return the favor.