Q. My boyfriend masturbates all the time. He denies it but I keep finding his nasty tissues. He knows it upsets me, so why won't he stop? I have sex with him every day.

A. Some of us masturbate because it's nice. Some do it to top up an unsatisfying sex life. But a small selection use it as a distraction from uncomfortable feelings, and it's this group your man belongs to. During orgasm, our brain releases mood-altering chemicals, which some find addictive. Sex addicts live in secrecy and shame. Masturbation is a compulsion over which they have no power and receive no pleasure. This isn't about you and he may need help. For more info see www.slaauk.com