Is my mum a perve or is this normal?!!?

When she is walking along behind me she always goes ohh you got such a nice little peachy bum or ohh your bum is so big Kieran she is always saying stuff about my bum and sometimes touches it when im walking along to imbarise me but it makes me self conches but she don't know this but im gay im 15 but yeah she always say i got a nice big bum or a nice little bum she is always saying about it is that normal?!!?