If you are a steady Dom(me) or a heavy Sub (meaning you [italic}don't] Switch) does the Sub in your relationship EVER penetrate their Dom?

First of all, i'm a lesbian, submissive masochist in a relationship with a lovely Woman i'm lucky enough to call Mistress. W/we have a D/s dynamic in our relationship that is as 24/7 as possible given that W/we don't live together. W/we have BDSM play but W/we also have vanilla sex, because sometimes you just don't wanna go to the effort of turning it into a scene, you just wanna get off, ya know? W/we have BDSM play that doesn't include sex, and W/we have play that does include sex, which can include cunnilingus, petting, vaginal penetration by fingers, hands or toys, strap-on play, orgasm, etc. All of the above can be from either side depending on the session and Her wishes. When W/we have vanilla sex, W/we are both continually conscious of the D/s dynamic but it's less prevalent. As Her sub, i have penetrated Her with my fingers, tongue, toys and strap on. She, of course, has the right to deny me that privilege if She chooses but She has never done so.