The 22-year-old spoke to Reveal about how the Made in Chelsea star looked like a "cardboard cutout" and was only after sex.
"He comes across on camera like he's looking for a relationship, and that's all about love, but off camera he said, 'F**k love, let's all just have sex'," the model from Norfolk claimed.
Sheehan also revealed how Matthews was embarrassed about his height, saying: "Anyone taller than him had to wear flip-flops under a long dress."
She added that Matthews's Made in Chelsea co-star Louise Thompson, who was in a relationship with Spencer, is not a fan of the show.
"She always tweets nasty things about the show and slags off the girls," Sheehan said. "She started following me on Twitter the other day."
Read the latest issue of Reveal to see Danielle Sheehan's interview in full - on sale now. The Bachelor currently airs Fridays on Channel 5.
