Mars is conjunct the cusp of the 12th house so clearly in the 12th.
The composite is the profile of the combination of both of you. Sex isn't just Mars; it is Mars and Venus.
Venus and Mars sextile each other, so there is opportunity for sex.
The Venus receptive part of your combined temperament likes your inner Martian energy.
Your asserting Martian energy is not so drawn to your receptive part.
That is what the reception between Mars and Venus points to.
So there are encouraging elements and challenges to the sexual relationship. With Uranus in the mix with Mars Venus, there may be surprises or non-traditional activity.