hi all. Curious cuck and need some advice

#1
36 mwm and just got my wife her first black dildo. She had been using the emperor which is not black, about 7.5 long and 2 wide. I got her the "bam" black dildo but were not able to get in her pussy, just too thick. I still think she can get there...but needs practice with something not as fat. What do you suggest?