Wow, that totally depends on the guy! Some guys would be hoping you say, "Thank you, but no thank you." Some guys would be offended if you didn't accept their offer. Some guys would expect far too much in return, some would be offended if you thought anything of it.
Goodness sake, just look at some of the guys who post on here about paying for a date's MEAL!! .....much less a meal and a movie...without her reciprocating with a blow job.