If she isn’t ready for anal intercourse but does enjoy a little anal play, introduce one lubed finger (or two) inside her anus during foreplay or intercourse. A good intercourse position for this is the side-by-side and face-to-face.
She puts her top leg over his top leg, opening up her anus for easy access.
He caresses her buttocks, squeezing them lightly and occasionally slapping them as he uses his other hand to stroke her clitoris.
When she’s highly aroused, he inserts one lubed finger into her anus. (He wears finger cots on his anal play fingers.) These little plastic gloves for your fingertips seem less intrusive than full gloves.
Remember: Never take a finger out of her ass and put it into her pussy. This spreads bacteria.
............