Friend's sister

Anon or delete

Hey all.

Yeah this is a little odd and i dont understand why but hey here goes.

I have a mate who i have known all my life, we are both 21 and his sister is 18, i have known his sister since she was little.

The thing is lately i have had a bit of a thing for her...it's not like i want her to go out with me as that would not be possible..can;t imagine the awkwardness it would entail around her.

I mean whenever i go around my mates she is usually there, she doesnt dress slutty..always is rather covered up..never seen her in a short skirt or low cut top for example...although she is a bit off the rails and has a temper at times (most girls do around here for some reason..maybe as its an estate i dont know)

Anyway it's really recently in the past few months i have been having thoughts about having sex with her..i don't know where this has come from..and the thoughts really turn me on.
She isnt stunning by any means but has a kind of cute look to her, quite tall, but not a proper stunner but i would say pretty.
Me and her do get on quite a bit more these days than we did in the past..we just rarely spoke for some reason, but lately we have got talking more in person and on facebook, the other week we had a laugh and had a few drinks near her house, just me and her.

I mean i know it's a bad thought, maybe it's because she is now 18, is matured (physically, quite big boobs considering she is skinny)
I wouldnt act on these feelings (she has a boyfriend as well..and personally it would make things very awkward around here with my friends)
but im not sure why i have really suddenly started having thoughts like this...i was thinking maybe because it's taboo...like a forbidden fruit angle.

Anyone else experienced this? or am i just a whack job? im interested to hearing your views and stories.

Jeeze, this is the third thread that I've seen this week with almost the exact same plot