I'm a big let-down for sex-mad lover

I SHOULD be the happiest man alive, but I’m worried my girlfriend’s a sex addict.

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INSATIABLE: He wants a normal relationship but she keeps cheating and using sex toys

She's clever and educated but no amount of sex is enough for her. She's cheated on me numerous times in our three years.

She's had affairs with colleagues, threesomes with gym buddies and one-night stands with blokes from dating apps.

And, if she’s not indulging in intercourse, she’s watching it online.

I adore her and have chosen to turn a blind eye up until now because I’ve always feared losing her - but how do I deal with a person who has no regard for relationship rules and thinks only of her own gratification?