Jack&#;s mum has small tits, but she lets us all play with them

Jack has been my friend ever since kindergarten. I have been going to his house since that time. His dad always works away from home at weekends so Peter's mum would just naturally look after us when we went around. At first she used to leave the odd top button on her blouse open, then it was all the way, then she stopped wearing a bra and asked us if we wanted to play with her tits and nipples. She taught us how she liked it and I had my first ejaculation in bed one night thinking about how she let me and the boys suck on her titties. Then she started wearing just panties and one day asked if any of us wanted to take them off. We all did. We may have only been kids. but we knew there was forbidden fruit hidden beneath that flimsy material. She showed us how to finger her, then eat her out. That was a long time ago and now we are all teenagers and get to fuck her every Saturday. Its only Peter's close friends so she does about 6-8 of us each time, or rather we do her. Since the first time she let us fuck her she only lets two boys in the bedroom at a time, so its not a gangbang, just us pulling a double train. Usually takes her about three to four hours, because most of us have a second go at her. Peter says she sleeps all day Sunday to recover. I think thats when she lets him fuck her.