My boyfriend won't accept my offer to loan him some money?

"I'm not the kind of person who would throw it in his face or even bring it up later down the road"...Ah, yes, you say that now. You yourself also said "Our relationship is a bit rocky". So I can understand his hesitation. More importantly, he probably knows he can't afford the trip so don't pressure him. Either GIVE him the trip or let it go.