Proposing marriage to one man and marrying with another man, is it allowed

 

Proposal of Marriage and Commitment

Islamic Ruling on Breaking Proposal of MARRIAGE

Answer

No,

It is breaking of promise and trust

It is sign of hypocrite

But, there is no sin on Husband

Parents will be responsible for this sin and they will be accountable

Refer complete answer

https://islamqa.info/en/answers/112078/he-promised-to-give-his-daughter-in-marriage-to-one-man-then-he-gave-her-in-marriage-to-someone-else