For my wife it’s purely about size. She says the first time she took my dick in her mouth she knew she would probably end up marrying me. I am big but she’d once been with a guy who was TOO big. I was “perfect”.
Ironically, the first time I kissed her pussy I knew it would end in marriage. I’d just never tasted anything as smooth and clean and bald as her little caramel slit. She was apprehensive about my size at first and the first time I came in her presence was in a nightclub toilet cubicle, skirt up, panties down, boots planted firmly on the floor, she didn’t want me to fuck her without lube so she jerked me off between her legs and let me cum in her thong. She pulled the skirt back down, the panties back up, and then came back to join me and my friends in the club, with my cum dripping down her thighs.
Needless to say that about an hour later, once we were back at mine with lube, I fucked her until the neighbours complained.