Addicted To Sex

I have been happily married for over 18yrs and had always been the faithful , dutiful wife, surviving on my perhaps twice a week sex regime, my twin sister on the other hand is just a slut and we fall out regularly over her promiscuity.
Last year at a bbq at hers she got me really drunk and had spiked drinks, when i had to get her to take me to the bathroom she invited two of her male friends in who both preceeded to have sex with me one after the other and i let them, to be honest i wasnt as wasted as i made out and actually really enjoyed it, first time i had orgasmed in ages. she apologised to me saying it was revenge for all the times id dug her out, which was no excuse , later that same evening ,this happened around 4.30ish, i motioned to one of the guys to follow me and i let him take me hard again in the spare room, all the while my hubby was outside.
Now i just cant get enough and have become a proper whore letting anyone willing have me