There is no direct relationship between cohabitation and recurrent mouth ulcers, and recurrent mouth ulcers may be related to recurrent oral mucosal infections, vitamin B deficiency, improper diet and other conditions. 1. Oral mucosal recurrent infection: long-term overwork, repeated exposure to cold and so on leading to a decline in the body’s immunity, do not pay attention to oral hygiene and so on may stimulate oral bacterial recurrent infection, mouth ulcers recurrent situation. 2. Vitamin B deficiency: patients lacking vitamin B2, vitamin B6 and other vitamin B may lead to recurrent oral ulcers, and in severe cases, lipitis, dermatitis and other symptoms may occur. 3. Improper diet: daily consumption of spicy stimulating, cold food can also lead to recurrent ulcers. After having intercourse mouth ulcers recurring situation should be timely consultation, please doctor clear diagnosis and treatment, daily attention to maintain oral hygiene, drink more warm water, avoid excessive sex caused by excessive fatigue, affecting the health of the body.