Picking up a store brand box of frozen treats might just be a way to save money, but a melodramatic ad from Unilever’s Magnum warns that it could bring down a whole relationship.

In the film from agency LOLA MullenLowe Madrid, a woman becomes suspicious of her partner after he buys a box of generic ice cream covered in milk chocolate. As she investigates their home, she learns that the man willing to buy “fake Magnum” has also falsified his athletic accomplishments and is even wearing a fake mustache.

She drives off into the night to get satisfaction from the real thing: a refreshing and sweet Magnum ice cream bar.

The brand said this is the first time it has used humor in its advertising since its founding in 1989.

“The territory of pleasure is difficult to build credibly for an ice cream stick, which is why humor is dangerous, but more than anything it’s because the brand has become very global, and humor usually changes depending on the geography,” LOLA MullenLowe Madrid executive creative director Tomás Ostiglia explained to Adweek.

“This is the first time that the brand has tackled a brief like this, and it was important not to sound arrogant or fierce,” LOLA MullenLowe Madrid managing director Tom Elliston added. “The melodrama allows us to cut this with an entertaining story.”

The campaign is running in the U.K. across television, out-of-home, print, point of sale and digital. Its success at combating imitators will be measured by tracking sales, market share and brand power growth.

“At Magnum, we work really hard to make the highest-quality, indulgent ice cream products, and we wanted to find a fresh way to tell our audience why it’s worth it for them to ‘stick to the original,’” Magnum London global vice president Ben Curtis said in a statement. “LOLA MullenLowe came up with a brilliant and funny way to dramatize our commitment to delivering true superior pleasure every time.”