We both were 29 and 20 back then. For a while my brother used to live with me. During his stay we got a bit physical with each other and we both helped each other get off. I used to jerk him off and he used to finger me back. I was pregnant at the time and his fingers felt so good inside me. Other than this we never did any other sexual acts like oral or sex itself nor were we curious about it. For us it was more like helping each other than engaging with each other in absolute sexual terms. After a while he moved out and we have stopped ever since and got no plans to continue it ever after.
Source: reddit.com/r/gonewildstories/comments/ldbt3y/f_my_f_31_bother_m_22_and_i_used_to_masturbate