It's more likely the wife/gf finds out, freaks the fuck out and threatens to leave unless "help" is found.
She starts calling his mom and entire family, her entire family, all her friends, complains to his friends (while hugging them), and starts a "make your life so horrid that a living hell would be peaceful" campaign towards you. OR she stays quiet to others but starts acting like you've gone completely off the deep end. Now, in both cases, to "solve it" according to HER experts, is a silly little thing called therapy where you're supposed to spill your guts and say it was too much sucking on mommy's boobs as toddler that caused your porn addiction.
*Cues tears on demand then starts sucking on the therapist's boobs* - WTF? He's a guy! OMG! Soo not gay! Damn you, wife!
All humor aside, this does happen IRL. You can get sent to inpatient or outpatient for sex addiction from being caught while over-fapping on the internet. You know you like that risk, tho?