Introducing something new to the bedroom

So I'm generally really submissive in the bedroom and always have been. My boyfriend is the first guy I've ever been with sexually at all. I have my moments of confidence but it's like getting on too or giving him head. But for the most part my boyfriend picks the position, speed, etc. Which is great because he really knows what he's doing in bed, but I'd like to try being tied up or possibly blindfolded. I just have no idea how to broach the subject to him. We've never done anything that's not really basic sex so I have no idea if he'd be into that kind of thing or how to ask him. I was thinking of just pulling out a tie or something and asking to be tied up when we're about to have sex? Or do you think having a conversation first is better?