This happened the summer when I was 13 years old and left a very deep impression on me to say the least.
I was at home fooling around in my room dressed in nothing but my underwear to keep cool (our home was very lax when it came to how one dressed in the house). I went out to the living room and saw that my mom was nursing my 4-month old sister. It was just us 3 living in the house as dad had been killed in a car wreck 6 months previously. Mom was sitting on the sofa with her head back; eyes closed; and Karen busily sucking on her breasts getting nourishment. I was watching when mom opened her eyes and smiled over at me. Soon my sister was through nursing and mom stood up and took her to her room for a nap.
On her return, I noticed that mom had not covered herself and sat down once again on the sofa with her milk-gorged large breasts staring out at me. God, those nipples were huge! Seeing my gaze she reminded me of when I was a baby and would nurse her breasts and how much she and I enjoyed the closeness. Mom then asked me if I would like to taste her milk once again as she still had plenty and that dad used to do so when I was through nursing...wow, I never knew that. I replied that sure, I would try it whereby she told me to come over to the sofa, lie down and put my head in her lap.
I did so and she cupped her breasts and guided a hard nipple to my lips which she brushed a couple of times before placing the nipple into my mouth. She told me to gently suck the nipple and the milk would flow out and I promptly did so. WOW! The milk started coming out and was so warm and sweet tasting that I eagerly sucked for more. Mom was enjoying my nursing as she was constantly uttering low moans during my 'feeding'. After a while she pulled out one breast and guided the other towards my mouth once again brushing my lips with the hard distended nipple before inserting it in my mouth for more nursing.
This whole episode was having a erotic effect on a 13 year old boy whose hormones are raging anyway and the inevitable happened; my underwear was noticeably tenting from my erection which was in plain view of mom. Looking over in that direction she gave a small cry of discovery and said 'oh my, look at what I have caused on my baby'. I said nothing; just kept on sucking on that lovely soft milk-laden breast for all it was worth.
She then shocked me by saying that since I was helping by milking her would I like for her to milk me like she used to do for dad. I only nodded my head in agreement as I wasn't about to let that nipple out of my mouth. I then felt mom's hand on my stomach and begin to slide downward under the band of my underwear and touching my erection whereby she and I both gasped at the touch of her hand. She then closed her hand around my member and began to slowly rub up and down on it; all the time giving out little moans of pleasure which matched my own. She then turned around where she was facing my groin and with the other hand slid it inside and cupped my testicles. This was more than I could take and had an intense orgasm whereby I shot my cum all over her hand and my underwear while still sucking her nipple. Ohh, it felt so good. Upon finishing my orgasm, she removed her hands and asked if I enjoyed the mutual milking session whereby I replied 'yes, very very much'.
She then surprised me by telling me that we could have many more if I wished and I spent the summer in nursing and milking heaven.