What is the ideal girth and how thick is too thick?

My FWB likes 6" with decent girth but she says that now as she is older, she'll take longer when she can. She thinks she's not as "tight" in any direction down there. She'll take me slowly but not in the ass. Well, one time in the ass but it hurt her. She and I prefer good oral so it doesn't matter too much. Someone here talked about matching parts and I think that's important.

 

Women are complex creatures, with different needs/desires at different times. And the penis/toy size can depend what they feel like doing and achieving at any particular time. For my wife, when she's desiring something bigger than me, she doesn't want to be fucked by it or fuck it. She just wants to expand her vagina to the point just before it gets uncomfortable and then stop and rub her clit until she gets off. She used to use a bottle that was 8.5" which is 2.7" across. It was tapered, of course. She would just sit down on it until she got the widest part in, stop, and rub herself off. For actually in and out fucking, she wants something far smaller.