Okay, I've went YEARS not finding anything about this, but here goes.

There was an OXO or Bisto advert that was hilariously out of character for what they were advertising and there were two versions of the advert depending on what time of day it broadcasted, this was early 2000's, maybe 2003-2005.

Here's how it originally went:
Group of friends are sitting together at a dinner party, they're looking at family photos together, all laughing and joking, a woman at the dinner table then lifts a photo only for a rotund middled aged gentlemen near the table to remark with something along the lines of "Haha check the state of him, he looks like he's got man-boobs!" to which the woman responds with "That's... my mother", then cuts to a shot of everyone's stunned faces as the tagline for the product appears

Here's the ADULT twist:

For some inexplicable reason, there was a "post watershed" version of this advert that I can find absolutely no evidence of where after the rotund gentlemen makes the "man-boobs" comment, there is a brief shot of the gentlemen, now full bollock naked with his own man-boobs on display. The tagline then appears here.