I wouldn't worry about it now. If he was goingto cheat, he would've done it by now, regardless of his profession. And yes, some girls might try to be slick, maybe even some guys, but I doubt he'd act on it.
My artist did my most intimate pieces. Those dudes are honestly so respectful and professional. He's tattooing because it's art, unless it's out of your kitchen and totally not legit. But tattoo artists are much more professional than that because they have a massive, big, important job to get done. I highly doubt he's interested in the girls, he just can't discriminate.
My baby father does tats as well but even if the dude is being faithful you have some females that will try slick things to get stuff free and what not
If you trust him thats good! & letting a comment that never bothered you until brought up by someone else shouldn't get to you thats their personnel trust issues not yours people like to say what they would do and what bothers them if they was you & if you all of a sudden get trust issues it might cause probs because u always had trust for him and now hes going to be confused on what he ever did to loose your trust when it was nothing but a comment always give some one your trust until they do somthing to not deserve it
Well,that's part of his job. He can't descriminate and only work on males.
I wouldn't be too comfortable to be honest. Especially, because women get chest pieces and what not. But hey...that's his job to do it and as long as he's being professional, than you can't get mad. Just try not to let it bother you :)