MATT GRANT will make the most important decision of his life on Monday night's episode of "The Bachelor: London Calling," when he gets down on one knee and proposes to either CHELSEA or SHAYNE on the season finale of the series in what is being touted as "the most romantic finale" of all.

Before he announces his final decision, ET spoke to Matt about why he thinks his on-air romance may be the first "Bachelor" relationship to succeed, and about his immediate plans for the future, such as will they set a wedding date?

But before the British bachelor makes his final decision and presents one of the lucky ladies with a $60,000 Tacori engagement ring, he takes them to London to meet his family -- his mother TRISH, his dad TONY and his brother SIMON -- who advise him on his final selection.

"The Bachelor: London Calling" airs Monday, May 12 at 10 p.m. on ABC.