BF has yet to go down on me


I need some advice! My bf and I have been seeing each other for almost 9 months now, dating officially for about 5. He hasn’t given me oral yet. When I asked him about it, he said he “did it one time when he was really drunk” which I think is a lie because he said I’m his first serious relationship. He said he’s talked to his best friend about it and is not sure why he hasn’t yet but he’s working on it. I’d like it but I don’t want to force him to do anything he doesn’t want to do. He said it’s not me but I think I’m overthinking. Is it me? Is he gay? Is he just nervous because maybe he hasn’t done it before?