International boyfriend is going to Disney World with his ex... I don't know what to do.

I feel horrible. Awful. I don't have a great feeling about his ex's intentions. Maybe I don't trust him 100% and he knows how I felt about all of this and he still went. I cannot control him.But I can be vocal about my feelings. His ex booked this trip in March before we got together. We've been together since April. Been friends and chat buddies on Skype since 2011 and realized we were highly compatible with one another. We've very communicative with one another.He paid for my ticket out there. He paid for the entire trip. I'm going there in 2 weeks to England and I'm in California. I'm 26 and he's 27. He can't stop talking about it. However... all of that money aside and him doing all of that - why do I feel hurt he's in Florida with his ex of 7 years? His ex is 47 years old and they've lived together and he just keeps telling me they're friends. But why would a friend go with his ex, to a place that they used to go to as people very much in love (disneyworld) and only be friends about it?I don't know what to do... I just need advice if I'm being controlling/insecure about it. Everyone I've talked to is straight and I've gotten much different answers from them compared to my gay friends. I'd figure I'd ask here cause a bunch of dudes tend to know how gay relationships work.I think from a technical and rational standpoint.. why would he go through all that trouble to get me out there if something was going on with his ex? But I think to myself.. I shouldn't be this hurt. As I don't have that many people to talk to about it or get an outside view... I figured I'd post here. See what feelings of mine should be considered okay and right or wrong.I understand I feel a certain way and that's not going to change. And I don't want to break it off.. I want this to work. He's gone through all that trouble to make it work. I just don't understand why he would go, and he just said "cause we're good friends and he bought my ticket for me". He doesn't have anyone else and doesn't have many friends cause of his anxieties and is clinging to this man because he's the only one that he can talk to. And I get it.But something doesn't sit right with me and I'm not sure if it's right to feel this way or I'm being an ass.