She is the side-chick but bae says he will marry her- Is he playing her?

A confused Diplomats sent us this. She is the unofficial official side chick, but bae is giving out mixed signals... Really confusing.

Read below and share your thoughts.

This guy has been asking me out for sometime now but I refused,but he persisted so i finally gave in since I didn't have anyone am seeing. I now found out he has a girlfriend imagine!

All their pictures are also all over social media. I tried breaking up but he said we're mature and can manage things..

So i just want to know should i just leave or keep up hoping he might end things with the other lady .  i asked where he sees our relationship in few years he said married with kid....

I'm confused ...    

 P.s he's very caring ,gives me all i ask for!