OMG that happened to me too when I was 17. I thought no-one was home and was fingering myself like crazy. Was about to cum when I see my moms boyfriend walk into my room. He was as shocked as me but told me to carry on and apologized for walking in without knocking. I was so horny I told him he could watch. His cock got hard and I told him to get it out. He came up to me and took over fingering me to an incredible orgasm. I sucked him till he came in my mouth and I swallowed it all.