How do i stand up for myself?

My husband is 7 years older than me, We have custody of his 7 year old daughter from a previous relationship, I know that he has no feelings besides mistrust for this woman and he loves me very much, but his family mainly my sister in law (his brothers fiancee) constantly talk about when he was with her or how much my step daughter (who i raise as my own) looks or acts like her. It really annoys me and i have to admit that i do withdraw from my husband a bit when i hear some things that he did with her. For instance i was only whinging to him about these comments the other day, that night we went to his parents and my SIL made a comment about how he and her used to "**** like rabbits and never left the room" yes it was like 9 years ago and i know that my previous relationships have been similar but i don't want to hear that about my husband and some stupid bimbo that he obviously loved enough to share a child with, it infuriated me and i went outside and cried cont....