On my 50th b'day, my wife stripped me to my b'day suit & put me over her knee on our living room couch, when in walked my mother-in-law walked in on us. I tried getting up to cover up, but my wife was having none of that & locked her right leg behind mine & tipped me further over & started spanking the backs of by legs. My mil started laughing as I was doing a lap dance on my wife's lap. My mil said this was a whole different side of me she hadn't seen before. She then asked my wife if she too could wish me a happy b'day, to which my wife said, be my guest. Before I knew it, I was over her lap & she began to spank me too. She then asked for my wife's hair brush, which she got for her, then held on tight, & started to paddle way. I started to do a lap dance on her lap before she too locked me down & pushed me further over & paddled my sit spot, & told me it was ok to cry & call her mommy. Which I did. She then asked my wife if there were any other family b'day traditions & she said yes. I always flip him over (he always gets excited from a spanking) & has very sensitive nipples which I suck & bite on after I blow his candle out. So my mil did, just before I couldn't hold back any longer, she came off of me to bite my nipple & finished me off with her hand, as I shot into the air. Now I get spanked by both whenever they think I need it, & on both of their b'days.