Chrissy Teigen ''can't wait'' to see John Legend use Viagra when he gets older.

The 28-year-old model is looking forward to growing old with the 'All of Me' hitmaker, whom she married last year following 10 years of dating, and is even thinking about how they might require the help of the erectile dysfunction treatment to boost their sex life.

Speaking to Us Weekly magazine about how her life has changed since tying the knot, she said: ''I think you are just more comfortable talking about the future more. I was the kind of girl that never talked about marriage and kids ... [Now] you just end up talking about everything as forever which is very cool.

''It's nice to be able to be like, 'I can't wait to see you with grey hair, it's going to be hysterical.' Or, 'I can't wait until you have to use Viagra.' ''

Meanwhile, the brunette beauty is planning to have ''a lot'' of children with the 35-year-old singer but admits their conflicting work schedules make it impossible for them to start trying for a baby at the moment.

She explained: ''I want a huge family. We want a lot of kids. When it happens, it happens. For us it's hard because he's on the road so much and I'm working.

''People think it happens so easily ... but the stars really have to align to have a baby and it is a little miracle so when it happens ... we will be so happy.''