Tulisa said to be especially worried with her N-Dubz bandmate's relationship with former Made In Chelsea star Chloe Green.
According to an insider Fazer and Chloe, who met through mutual friends, started texting each other when the 25-year-old was recently on holiday with Tulisa.
The insider told the publication that he told her that is she has not decided on marrying then she could not tell him who he could speak or could not speak about it.
Aside from the marriage proposal, Fazer, real name Richard Rawson, also said to have asked the chart topper in quitting her job on the ITV reality show, X Factor.
"If I can't find it at events where I'm surrounded by people similar to me, in the same industry, I doubt I'm gonna find it in a contestant." Tulisa - voted the world's sexiest woman in a poll by FHM magazine - added she'd never get romantically involved with someone while they were still appearing on the show.
She said: "I'd never date someone I'm mentoring, or any contestant while the show is on.
She told The Sun newspaper: "If I find someone who's a good guy that I get along with, I don't really care what he does, and that goes for anything. The one is the one." However, the singer - who was left embarrassed when her ex-boyfriend Justin Edwards leaked a sex tape of them earlier this year - warned she finds it difficult to meet new people who interest her.