Is it weird that my Bestie and Bf/ex Bf get along so well?

My Bf recently Ex but hopeful that we will get back together.. Gets along with my best friend so well. she looks just like me and acts just like me, we both have very simular personalities. sometimes i think they get along to well and laugh all the time,so loud and i feel left out! and it frustrates me.

They are both Extremley Loyal people. He is so very against cheating and is very honest, sometimes too honest. and she is the type of friend that would never jeopodize our friendship. so i feel very bad for thinking this.. but its something that is natural to me to think that. Also cause i know he thinks she is very attractive and wanted to have a 3some with her and me, because my ex and i had a 3some with her a year before. But its so different cause im IN LOVE with Him.. and i dont want it to happen.. we all agreed it would be weird if we all were to do it and dont want to anymore!

he says to me he thinks she is a cool chick and she listens to him, he said its just also good to have an outside opinion, coz were in a relatinship, there is my opinion and then the outside opinion.. he would sit me down and explain this to me cause he could see i was worried..

He was very serious to me, he got Tattoos, and constantly told me he wanted a future with me... Am i silly for tinking this or is it natural?


Updates
Today, i found out my instincts were right All along!! I found out he has feelings for her and is moving to were she lives to see how things go! I talk to her last night and she acted like she was so oblivious to this situation, and was upset that i would even think this.

I found this out through a reliable Source someone,he told her cause he thinks i would never talk to her ever. His tattoo artist. i dont even know her.. what an amazing chick!

I knew i was never Stupid yet here they are making me feel like i was so stupid to ask and think this. and he tells me if he finds out If ive been seeing any of his friends anyone he knows or hates he will make my life hell and will hurt even his friends. What kind of person Is He. A pathetic excuse for a man. He want everyone to know we. left on good terms coz he is so worried of what ppl think. He doesnt deserve respect or a good chick! How could he do this to me when he has had this done to himself.. all the things he said he would never do and swore by them cause he has been so heartbroken before!

Listen to your instincts!