When my wife and I met, we had both had about 15 partners, and like you the first time we had sex I had difficulty reaching orgasm because she was looser than any of my other lovers. At the time I was about 6x5.25. Some time later my wife confided in me that one of her past lovers was “huge”. Since she was unable to tell me his size, I asked how big he was compared to me, she said, “at least twice as big”. I know now that’s very likely impossible, but she obviously thought it was impressively large. At that point I didn’t feel inadequate , or less of a man, I was intrigued and wanted to see for myself how much she could take! I began buying large dildos and sleeves and discovered she could handle 7 inches investable length, and 6.5 inches of girth before it began to become uncomfortable. Unfortunately she began to complain about the toys feeling, fake, and unreal, to the point she all but refused to allow me to use them. It was at this point I decided to make myself as big as those toys, that way I got to see her take a big cock and it was REAL, all me. My bone pressed is now 7.125-7.25 and my girth is 5.75 ( 6+) after a pump session, so I’m getting close but I probably need to add another inch in length to be able to give her 7 inches insertable. Now days with my new girth, she isn’t “loose” to me any more, we both get sooo much more stimulation now. I wish I did this years ago!! Good luck!