unfinished sex

sam
so me and my boyfriend just started having sex .. the sex is good as hell but for some reason he never nuts and I never really cum.. the head and foreplay and just the sex in general is good but I don't understand why he can't nut... at first I thought it was me like I was doing something wrong but he always tell me it's not me because he still wants to continue and keep going .. but it just takes him forever .. well it takes me forever too but idk what to do !! I feel like after a while the sex is going to get played out .. I need some advice.. I really like this one lol