Over the course of its seven seasons, '30 Rock' made no secret of its unabashed love for all things 'Mad Men,' including both stars Jon Hamm and John Slattery on the series and rattling off a number of random references in between, but did 'Mad Men' return the favor in this past Sunday's "To Have and To Hold"? It seems a certain 'Mad' man's drink order paid homage to a fictional drink from '30 Rock,' so find out about the subtle gag inside!

We've long revered 'Mad Men' to display the utmost class and sophistication in its narrative, but it seems the writers of this Sunday's "To Have and To Hold" might have pulled a fast one on '30 Rock' fans. Following a climactic scene of the episode, character Ted Chaough was seen to order an "Old Spanish" at the bar, referencing a non-existent drink mentioned in '30 Rock' episode "Governor Dunston"!

The drink in question contains red wine, tonic water and olives, and was mentioned by Matthew Broderick's recurring character Cooter Burger, with no base in any real-world drink. Noted '30 Rock' writer Tracey Wigfield first pointed out the reference over Twitter, though AMC has neither confirmed nor denied the apparent homage.

'30 Rock' might have closed its doors, but we're happy to see it's impact in the future...or the past. Go inside the latest episode below, and tell us what you think of the current 'Mad Men' season in the comments!