a few rules...
always try to have sex at their place, or in a strategically parked vehicle.
always have something to do immediately after, that you casually mentioned during dinner so it is believable later.
anytime the power/lights suddenly go out, you dive for floor and draw weapon, remain lying prone.
always know where your pants, wallet, shoes and gun are. never leave in living room to have sex in bedroom.
try to block bedroom door with your shoes, a book, whatever is close. you wanna hear something fall if you're getting creeped up on.
Times are tough, so there's always the possiblity she's banging you while her man sneaks up to crack you in the head.
Also, she will likely hide any crazy ex's or current husbands, who come home suspicious and decide capping you is more than fair.
Really, get to know them first - develop a circle of female friends for about 6 weeks. You can weed out the nutjobs and develop a steady circle of trusted companions for dinner, dating, whatever.