I told a really stupid lie to my boyfriend a while back, and now I need to fix it because he's meeting my parents.

When I first met my boyfriend he told me he was a PhD student, and I responded to something he said by explaining my mom has a PhD, which she doesn't. That's the only lie I have told to him, and did it because I didn't know what else to say.

Now he's coming home to meet my parents, and I don't want the education/PhD student to come up and have everyone be confused.

Will it come up? How do I avoid it? Is there something I can say? I really don't want to explain to him that I lied, because I don't have a logical answer for it, and I'm worried he'd second guess what I say.

Thanks!