Hook up or not? guy or girl advice please!?

how can i tell if a guy wants to be in a relationship with me or just wants a hookup? some info- we have been friends for months and is currently single. we talk about having sex and he has asked me to give him a bj. we havnt done anything yet. besides this he is very sweet and we tell eachother everything. are there any signs that anyone can see with this to know if he wants a hookup or not? are there any signs just in general? please give me any advice you see fit.