Is it normal t

My elder brother got married 4yrs ago and was living and working down south but last year mum had a heart attack and was left partly disabled so I became career for mum should mention mum can't use left arm has limited speech dad passed away 10yrs ago car crash .as I'm looking after mum my brother and his wife moved back up to help with mum care over my brother goes to work and we look after mum over the past year we have started having feelings for each other she noticed I was getting erections on when she bent over and I could see her boobs .i was in my bedroom on this occasion having a masterbating session she walked in she didn't say anything just watching I carried on just looking at her I didn't ask she lifted up her skirt and removed her tights and knickers revealing a lovely shaved pussy I shot my load onto my stomach she came over and helped me clean up .she said what a waste .next time ask and you will receive? What do I do and is this normal behaviour for a married woman