Claire Danes with fiance Hugh Dancy. (WENN.COM)

Claire Danes is turning to friends for advice about how to stay faithful as she prepares for her September wedding to Hugh Dancy - because she wonders whether monogamy is "realistic".

The Romeo + Juliet star, 30, will be a first-time bride next month, when she is set to exchange vows with 33-year-old Dancy.

The couple plans to return to France for the nuptials, where Dancy proposed during a romantic holiday last December.

However, Danes is already preparing herself to avoid temptation.

The actress explains to BlackBook magazine, "I was talking to my friend about (whether it) is feasible, is it realistic? I resolved that there isn't really a better model. We just can't shake monogamy. It definitely demands a kind of rigor and discipline and selflessness. But it's also fun."

The couple has been dating since they met on the set of their 2007 movie Evening.