What should i do?

i have been living with the bf for nearly 4 yrs now.he is 44 nd have two kids from two previous relationship one 12 living in paris nd the other one 6 living with us. i guess i was in love with him nd when i first met him he told me that he will never get married again and he dont want kids i guess because he believe that kids get hurts when the parents break up? now three weeks ago i met the long lost bf of seven years ago we get talking again nd in a way he is offering me evrything that i may neva have. the problem he is doin a captain course on a tanker for 8yrs but he comes ago every six mths. the problem is i fil like i wna be with him the problem is it is worth it?how commited are we to make the relationship work for 8yrs and will i hurt my present bf by just living him. i know i havent been hapi 4 longtime nw i have the chance to move but still i cannot! i want something which is mine something that we both want something that will last that i dont have 2 keep looking for it.