My sister walked in on me masturbating...?

Aww.. That's really awkward, you know.. But just leave it that way.. It's normal to masturbate, i mean.. It's not that normal for some people, but it's ACCEPTABLE especially nowadays.. (it's 21st ******* century) lol.. It's your sister. I know she'll understand that you are in a "needy" mode that night.. But if you're really uncomfortable, talk to her.. Like, just say "hey, i know it's awkward but i don't want you to have a wrong impression on me" etc.. Hehe! I hope i'm being helpful.. And sorry if not =)