Ex bf, fell back into him, hes got....?

well i went out with a guy i rly liked in the beginning of the year. we had so many good times and memories but we broke up after 4 weeks becuz our friends hated eachother. his friends didn't like me or my friends and my friends didnt like him or his friends, haha so yah on with the problem, well i tried datin sumone els, it was hard, but i still rly like him, i was hanging out with him alittle while ago and i just missed everything we had. he told my little brother he still liked me, but he has a girlfriend, Savannah, i know her and shes just gunna end up hurting him if they get close. should i tell him im still into him and that i miss everything, or should i sit back and forget it, keep being just friends??? wut move should i pull???