^Your priest is correct.
St. Dionysius Canon 3. Persons who are self-sufficient and married ought to be judges of themselves. For we are told in writing by St. Paul that it is fitting that they should abstain from each other by agreement for a time, in order that they may indulge in prayer, and again come together (1 Cor. 7:5).
Interpretation (from the Rudder):
And when asked about husbands and wives whether they ought to be continent respecting each other, the Saint answers that on this point the parties themselves ought to be sufficient judges, since it is fitting and proper according to blessed Paul for them to engage in no bodily association and intercourse when they are indulging in prayer; and this course ought to be adopted by agreement between both parties — that is to say, by both the husband and the wife agreeing thereto — lest it should come to pass that one of the parties is tempted by the enemy, and the continence of the other become an injury to the one so tempted. For if one party is overcome by desire and is not permitted by the other party to enjoy the satisfaction of it, he is liable to fall with another woman and sin, according to Zonaras.