That really depends on where you are going and where you are coming from.
In general, if you are going to a place that recognizes your union (civil or not, heterosexual or not), have paperwork to back it up, and have been sharing your life as partners for a while (ie shared financial responsibilities etc), you should not have any more trouble than non-ace couples.
Believe it or not, outside of weird sexually perverted cults like the Roman Catholic Church, having sex is not a requirement for marriage.