It is difficult for me ever to endorse adultery as opposed to divorce. I think your suggestion about communication is correct. Talk (not accuse or scream) to your spouse/partner. Try to find out why there is a dead bedroom. You are correct that the initiator of the conversation may be partly or fully at fault.Both must be humble enough to accept they may be at fault. See if things can be repaired by the couple or with counseling. If not, and assuming sex is important in a marriage-it almost always is-then end the marriage as quickly and as amicably as possible.