How do I tell my parents about my older boyfriend?

Ok, here’s my problem. I recently started seeing this guy, we’ve been together now for almost 4 months, and I am truly happy and in love with him. I have yet to tell my parents about him, even though I’m sure they’d be thrilled for me to have a boyfriend again, we have an “issue” standing in the way. I’m 22, and my boyfriend is 42…yes, that’s 20 years difference. I never think about the age difference until it comes to needing to talk to my parents about it. Even though he is 42, he does not act or look or anything like 42, I always say he could seriously pass as a 35ish year old, IF that old. So, my question is…how do I tell my parents about him? The age problem doesn’t bother me or my boyfriend, we’re just afraid of what my parents will think once they know. Even though I’m an adult, my fear is that they will try to “refuse” me from seeing him. I have had friends tell me to just take my parents to dinner some night (they live an hour from me) and tell them I have a boyfriend and just see where things go from there. I want them to know about my boyfriend because we’re ready for things to be out in the open and tired of trying to keep things from them and I’m ready for them to meet him and get to know him. Like I said, I’m very happy and in love with him, and to me that’s all that should matter, right? Age is just a number, right? So I’ll take any suggestions at all on how I should tell my parents…