Lots of times since she like a finger back there specially when I am eating her out. Always wait until she is dripping a lot, or wet my finger(s) in her c*nt before going to the back. Never dry to make it uncomfortable. That finger(s) will be the backside one until we are finished. Never mix the backside and the frontside while we play.
Besides the thrusting, she like my curled finger pressing back out from the inside. Scissoring my fingers apart to stretch her opening some. She has a favorite smaller vibrator she likes up there when she's in the mood for something larger back there. So sexy when I DP her with that vibrator and a larger dildo in front.
My fantasy would be her DP with two regular size dildos, or a VDP with the two. But she is not as adventurous as her younger days.