How do i stop being jelous of my boyfriends ex girlfriend?

[violeta]

Hey i really need some advice on how to get over my boyfriends ex.
I have two years with my boyfriend already and he is the first boyfriend i have been this jelous of...
When we berly started going out he would talk about his ex alot! (even though they were boyfriend and girlfriend for about 5 month) He would even tell me how their sex was ,how they would do it, where they would do it etc.
No other boyfriend had told me so much detail of their ex ... but i thought he would stop telling me everything. When we were about 5 months i went to mexico for about 2 weeks and i know it was wrong but i went through his messages on facebook and found out he was talked to her when we were about 3 or 4 months together, THATS WHEN I EXPLOTED. I tried to break up with him but we were just so connected with eachother... After that i found out that he had gone tk her house to go "visit her family" so all the trust i had for him jist broke!
Ever since that and ecen though we already live together and hace 2 years with each other i cnt forget what he did and cant trust him no more even though he didnt cheat on me with her i guess i took it like if he cheated ...
And it was bad enough his mom and sister would act like if they knew her for so long or if they went out with each other for years i just dont like that.

Know all i know about her is that he has a baby and happy with her boyfriend...
And even though i have everything to be happy with my boyfriend i still cant get over him going to visit her ... Speacially because he said nothing happend ..
And now are viggest fights is when i bring her up and try to talk about his past ...
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What im more jelous about is COME ON THEY JUST LASTED 5 stupid month and it was just per sex and he cried for her so much! And got all depress and emo about a person that didntevn live him and that cheated and he got over her like after a year ... A lil before he met me and supposly felt in love with me right when he saw me ...