>Had to go to a funeral 2 weeks ago for an Uncle
>Niece, who's 18 now (I'm early 30s) speaks to me for the first time in a year or so
>Since she turned like 14, she's been wierd with me, trying to gets me alone, undresses when she knows I'm near, tries to walk in on me in the shower, tried to kiss me once etc.
>Generally just avoid her now
>Tells me she's 18 now and makes a little move on me at the reception
>Resist, and think it's done
>That night, she gets my address from my Dad and just drops by my apartment in lingerie
>Fucking tired from the funeral, horny
>Have fuck
>She's been coming to my place since that night and we've been having sex
>Last night we bone 3 times and she says she loves me and doesn't want anyone else.
I don't know what to do now. I feel like I made a mistake I can never recover from. My half-sister that's 40 now is going to go batshit when she finds out, and I know it's going to happen. Obviously, no one knows yet, my niece is fairly independent and my sister is busy with work so she usually never she's her daughter anyways, but fuck man, there is no way this works out okay.

If I break it off, she's going to go crazy, I basically just have to hold on and hope she moves on from me.