A hopeless romantic was stabbed to death by a paranoid hobo as he attempted to bike from Connecticut to Miami for a surprise marriage proposal to his girlfriend, cops said Wednesday.

Avid cyclist Kevin Adorno, 28, had already pedaled 1,200 miles from his home in Farmington with the engagement ring in his pocket — and was 130 miles from popping the question — when he came across vagrant Rene Herrera Cruz in Vero Beach on Monday night.

The deranged homeless man spotted the successful graphic artist talking on a cellphone in the parking lot of a McDonald’s.

Adorno was chatting with his gal pal, Elyse, about meeting up to make the final trek to Miami together.

In Cruz’s twisted mind, however, Adorno was plotting to do him harm, according to a local police affidavit.

Without warning, Cruz drew a 12-inch filet knife from his waist band at 9:30 p.m. and slashed the bicycle-riding romantic across the chest and arms, opening massive wounds.

Elyse told cops that the last thing she could hear was the phone being dropped and then the sound of sirens.

As Cruz fled, Adorno staggered back into the McDonald’s and collapsed near a bathroom. One witness, who attempted to help him by placing pressure on his chest, said his wounds were so deep that it felt as though his hands were on Adorno’s heart, the affidavit said.

“Cruz admitted to stabbing Adorno,” Vero Beach Police Chief David Currey told local TV. “He stated that he thought Adorno was directing other people via cellphone to attack him, and Cruz therefore felt threatened and attacked Adorno.”

Cruz, who stole nothing from Adorno, including the engagement ring, tried to hide the knife by tossing it into a bush as he fled.

He was quickly arrested and charged with first-degree murder. He is well known to local cops, who had an encounter with him just the night before, according to NBC News.

“He called us from Burger King right across the street, and he told responding officers that individuals were looking for him or were after him,” Currey said.

Adorno considered the ride down the East Coast something he wanted to cross off his “bucket list.”

The Central Connecticut State University graduate was mourned by close friend Kenneth Silva as, “just a pure soul, as charismatic as anyone could ever be, smile from ear to ear, always generous,” according to the Daily Mail.

A photo album on his Facebook page titled “The Big Bike II” showed recent pictures of Adorno making his journey, which began in mid-August.