It's brilliant, I wind up my MiL all the time. I rejoice in the fact that she'll be explaining – nay, insisting – to the less credulous members of their Cotswoldian bridge club that not only has her son-in-law eaten a bat, he's done so in Nandos. That Bat Nandos is indeed a thing. They grill entire bats. Or a half, if you'd prefer, with two regular sides. And bat wings, don't forget the wings. So crisp! The even have a tagline: Come on, have a cheeky flutter! It takes some time because she's not entirely credulous, I have to work it in. But my job is done. It's double fun, because like most elderly white people in the Cotswolds, she's a bit scared of Nandos on account it's where black people and lesbians* might hang out. It's the sort of place they might have in Yate.
My other current con was hatched by my wife. We were sending MiL a picture of ourselves posing on a rooftop in Kuala Lumpur and knowing my MiL's hatred of facial hair and the fact I wouldn't be seeing her for a while, well what if I started photoshopping increasing large beards on my face in any photos? So I now look like someone from ZZ Top who's let himself go and she's suitably concerned for my appearance. Oh, you really should talk to him dear, it looks awful!
*The fear of lesbians is sort of, en passant, our fault. She was visiting once when we had two friends over, and well, let's just say they're both sapphically inclined and filthy-minded so when my MiL innocently asked oh, what do you do? they took a moment and replied in perfect unison: in bed?