Should i give up on my marriage?

my husband flirts & gets really personal with other girls, & which bothers me very much, he tells me u dont need to worry abt anything as long as i dont sleep with anyone. I dont know how to react, bec there is a thin line between flirting & cheating, im very confused. everytime we go out i catch him looki at other women, & i get really upset & we end up fighting, this morning i gave him a hug & kissed him & told him that i love him. he said i love u to and all my h---.& then he started laughing & said i was joking.he doesnt understand how much it bothers me, bec then i think abt it all day that what is he up to now, who is he talki to. should i just give up and trust him or keep fighting until he realizes how much it bothers me & he needs to understand my feelings. PLEASE HELP.