over came negative feelings to positive

My ex husband and his married next door neighbor have become the best of friends since I moved out in october. Lately she is there all the time and it seems like all I hear from my children is L this L that. It has really taking a toll, I guess its just being jelous but I feel I want to remind this women these are my Children not yours.  Today my 16 yr old daughter is telling me how L was at her fathers last night helping her pic out a tatoo online.  I started to shut down and feeling depressed, and she noticed, and asked what whats wrong. I stopped and simply said Im sorry bby I'm just being stupid, and I told her that I felt jelous of L. she was surprised and I said it's weird hearing you kids talk about her so much with things that we would normally be doing together. And I said I'm sorry bby don't take me wrong Im glad Daddy has a new friend, I just feel silly.  And I turned it into a positive and started asking questions and got her all happy about what they found and she told me all about it.  ALthough I was hurting so bad over it all. The idea of my 16 year old daughter getting a tatoo is out of the question, but thats a battle for another day, she can talk about wanting one all she wants........Getting it will be a different story, and if L keeps pushing the idea us two women will be having a talk about who gave birth to who, and I promise my wrath is harsh, and you put my kids in it. Look out. I'll make Tom Brady look like a rookie!!!!!!!!!