First time shared SeXStoRY

This is a true story about my ex wife. Shortly after my ex and I started dating and having sex, we began exploring each others fantasies. I was 20, she was about 3 years younger than I was and very adventerous. She told me she had been with her girl friends and was openly bi, and I was lucky enough to watch her with a friend a few times early in our relationship. We talked about threesomes, both with girls and guys, she had group sex fantasies... I lived with a good friend, Dave. She and I spent a lot of time at my apartment (since she still lived at home) and soent most of that time in my bed. She had a great little young body.. 5'5" or so, long blonde hair, pretty girl, slim toned body, 34B breasts with amazingly suckable nipples, great ass and tight bald pussy. We talked about threesomes and fantasized about it. one day we were fucking. I had her on her back, legs spread wide open, fucking her tight pussy while she pulled and pinched her nipples. We heard Dave come into the apartment and we whispered to each other hot hot it would be if he came in. I made her cum, it was thick, and creamy cum that just soaked her little pussy. I got off her to her suprise, wrapped a towel around me to try and hide my hard on, and told her to not move. I went out, into Dave's room next to mine and asked him to give me a hand with something. He looked suprised but came with me, into my room where she was still naked, spread wide and rubbing her clit on my bed. He was very suprised.. he looked back and forth between us, and after I said "Help me fuck my girl?" he stripped off quickly. She sat up and we got around her and she took turns sucking our cocks, moaning and squirming below us. It was obvious she was loving where this was going. I stepped back feeling myself about to cum, wanted to last a bit longer. Dave laid down and she straddled him in a 69. He dove into her dripping pussy while she took his cock in her mouth. Daves tongue focussed on her clit and he fingered her and groped her ass..She came again. She spun around quickly and before he even knew she sunk his cock into her pussy, letting out a loud moan.. She started riding him quickly. I got back into it, sucking her bouncing tits, and kissing her mouth, I could taste cum.. I added my own to her mouth again while she rode dave. I grabbed her and moved her down the bed. I started fucking her doggy style while she sucked his cock again. It was so sexy seeing her head bob up and down on my friends cock. I was pounding her hard, I could feel her cumming again, as she tightened I felt my cock throbbing and I filled her pussy with my load as she came too. Within seconds dave moaned and she had trouble taking all his cum in her mouth, it dripped out a bit down her chin. We smiled and laughed a bit with what just happened.. Dave said "wow...and here I thought I was going to have to jerk off again just listening to you two!" He left, and I looked at her, laying on the bed, breathless and cum dripping out of her pussy and over her lips and neck. We kissed deeply before heading for the shower.. That was the first of many threesomes with Dave involved, and first of our group sex adventures.