The girl Shalini and the youth Naveen got engaged in May last year. Both of them used to work together at a mobile centre, they said.
However, the girl's mother later changed her mind and Shalini was engaged to another youth.
Agitated with this, Naveen reached her house last evening and threw acid on her face and feet, before allegedly consuming poison.
The family members of the girl rushed them to the district hospital from where they were referred to Meerut, but Naveen died on the way.
Deputy Superintendent of Police Rajesh Kumar said the matter was being investigated.