Jealous Sister

I (20) got caught fucking my sister's best friend (25) by my sister (25). She was unhappy I had fucked her best friend and I didn't realize why at the time. My sister had a crush on me, and she thought she wanted to be the one to take my virginity. But I had already lost my virginity to my boss (53), she was a horny old gal and had asked to fuck her and I had agreed. Everything I knew about fucking she had taught me, and my sister thought her best friend taken my virginity. Actually, I was still fucking my bass regularly even those she was engaged to marry. My sister waited until we were alone and asked me straight out, why I'd let friend take my virginity. I told her she hadn't as I had lost my virginity at 18 to my boss. My sister shocked by that, asked how many partners I've had counting my boss and your friend 2 and added I had seduced her friend and she hadn't seduced me. As we were alone, and I had realized my sister's interest in me. I asked her for sex and then just kissed her and took her to my bed and fucked her. That was last August and I'm still fucking my now remarried boss, my sister and her friend. Never together, I am averaging at least one fuck a week, mainly from my boss. But my sister has promised me something special for my birthday next month but hasn't said what it is.