The JLS singer and The Saturdays member will tie the knot this summer and while details are being kept under wraps, Aston joked he has taken charge of the entire event and can even see a new career for himself.
Aston - who is currently single - said: ''I'm planning the wedding, I'm sorting it all out, I've got a new career as a wedding planner, I'm planning my own wedding at the same time, all I need is the bride.''
Although he proposed during a post-Christmas break in the Maldives, Marvin says he hasn't thought about an exotic location for their honeymoon because marrying Rochelle is the most important thing to him.
He said: ''We're both very busy but I've got the most important thing which is the right girl so things will all fall into place. It's this summer, I haven't been too worried about sorting out time off for a honeymoon or whatever because the most important part is the official tying of the knot, that's all I'm concentrating on for now.''
Meanwhile, their bandmate J.B. Gill revealed he and his long-term girlfriend Chloe Tangney did feel some pressure to wed after Marvin and Rochelle announced their engagement but they have no plans to follow them down the aisle just yet.
J.B. said: ''When they announced the engagement me and my girlfriend were getting a bit of pressure from people but luckily it's all died down now and everyone's focusing on Marvin and Rochelle.''
JLS - Marvin, Aston, J.B. and Oritse Williams - teamed up with Mastercard for its exclusive Priceless Duets competition, which supports its 14th year of partnership with The Brit Awards.
For your chance to win a Priceless Duet go to www.somethingforthefans.co.uk. JLS's competition is now closed, but there's a Priceless Duet with BRIT award winner Jessie J still up for grabs.