My BF is HUGE Flirt?

So, before we wnt out he flirted a lot, and now its liek he is more focused on other girls. He has girls all over him! ALL THE TIME and people are trying to take him away right in front of me. I think im too quiet, because i dont talk when it comes to his business, but i want to make it obvious that he is mine without making a fool of myself. What do i do to make him more attracted to me again and be more outspoken?