People often ask us how long they "should" wait. There isn't an answer, and anyone who gives you one doesn't know you. Some people feel ready within a couple of years; for others it takes much longer. Some never feel quite ready, but decide to have a conversation anyway.
Wanting companionship again is not a betrayal of the life you shared. It doesn't replace the person you lost or the years you had together. It sits alongside them. The people we introduce our widowed members to tend to understand that without needing it explained.