My boyfriend says im better than him at football, but im not and it makes me feel like a man ?

I met my boyfriend playing football at the courts, he's really good but he thinks he's not , when he told me he fancyed *someone* when we were flitring (meaning me) he said that the only problem was that 'she' was better than football than him. I dont't know why but it made me feel manly and im not a tom boy i just like playing football and im alright at it and played it since i was 5 and now im 13 , we now go out and , everytime we meet we play football , because its all there is to do , and we both like it ,but i dont like playing good in front of him because he might think im better than him but im actually not , hes way better than me , i mean iyts obviouse , hes a lad and , he just is better than me , also , answer this please , why does he say to me that hes not good at football ? his friend says that he isnt iether and he actually is the best player in the courts . what can i say to my boyfriend to make him believe hes better than me , im scared hell dump me because of this , im scared and im going to stop playing football with him , if i dont find a solutuion:( please help im really unhappy , if it wasnt for this , me and my boyfriend would be a right good couple , and if i dont play football with him there will be nout to do and hell think im boring and finnish me , please please help me :(